As many of you know, I really got my start on MTGO. Playing online is what really honed my skills, and certainly helped me form connections to other skilled players. I actually met Cheon through MTGO, as had played a few times prior to actually meeting at Pro Tour Philadelphia. It is no surprise that I would recommend that any serious player be at least somewhat acquainted with online play, since it is by far the most convenient way to practice most formats.
The biggest objection that most people have to MTGO is the price, as drafts cost 14 or 15 dollars and buying into Constructed can be a daunting endeavor, particularly when one already has all the cards in their physical collection. It really isn't that hard to "go infinite" (aka, never have to spend money to draft or play constructed) past the startup costs, and this article should help shed some light on the process. It is all pretty simple, but it is a very common question (I noticed someone asking FFfreak that in the comments of his last article), so I figure it is worth going over . I am going to assume that you have not a single card online, and go from there, although most people have done a few drafts at the very least. It goes without saying that you should take some time to be comfortable with the interface before entering any tournament, but keep in mind that you will lose to misclicks from time to time. I even do, and while it is annoying, it is part of the territory. I personally spam f6 all the time (which passes all your priority for the rest of the turn), but I would advise newer players to never use f6, as it leads to missed land drops on Turn One for those unskilled in its usage.
Yup, that really is it. The secret to going infinite on MTGO is to play Constructed, more specifically Standard. I would be remiss in my duties if I left it at that, but if you wanted the Cliff's Notes version, those two words would be it.
Build a good Standard deck
There are a few criteria when deciding what Standard deck to build. Cheap is ideal, since buying a whole deck from scratch is fairly expensive. Even though cards are generally cheaper online (since there are basically no transaction costs), you do have to pay for everything, from Vivid Creek to Cryptic Command. The first hurdle you have to overcome is the initial cost, so don't be intimidated. Yes, it seems like a pain to buy a set of Cryptics and Reflecting Pools when you already own them IRL, but you aren't just throwing your money away. These are real objects, and you can easily resell them if you desire. It always bugs me a little when people rail about "wasting" money buying stuff online; just because the cards are digital doesn't make them a black hole.
Anyways, back to deck selection. When I started, we (me and my roommates at the time) build KCI, the Krark-Clan Ironworks deck (Manuel Bevand's deck, found here), that killed with Myr Incubator or Goblin Charbelcher. It was basically strictly worse than Affinity, since it lost to the same hate cards, was maybe a little faster, and lost terribly TO Affinity itself. Disciple of the Vault made it pretty tough for the deck that needs to sacrifice all its artifacts to win.
Still, KCI had one advantage: It was really cheap to build. We had looked at all the decent Standard decks, and KCI was by far the cheapest, probably clocking in at less than 30 dollars (since we had a bunch of the commons and uncommons already). Once we had that going, we won enough in the 8-man queus to build Affinity proper, and from there we went infinite quite easily.
My point is that there are often decks that are much cheaper than others, and if you are under budget constraints, or as in our case simply don't want to spend much actual money on MTGO, and the cheaper deck can often be good enough to get you started.
I don't want to examine all the decks in Standard for price, since I have no idea on current pricing, but I would imagine that something like Red-Black Blightning is much cheaper to build than Five-Color Control, and both are probably good enough right now for you to win with.
You also want to keep the timing of set rotation in mind. Two years ago, Faeries would have been an excellent investment, but now I would probably shy away. Even without considering if Faeries is good right now, since it is surely good enough for winning packs online, buying Bitterblossoms, Cryptic Commands, Mutavaults, and so on right before Lorwyn rotates is probably not the best use of your resources. Lorwyn is so overpowered compared to Shards that buying some stuff that will drop in value is unavoidable, but you will easily make that back once you start playing.
Play the biggest Standard tournaments you can
The awesome thing about playing Standard online is that you don't have to have a great win percentage to be a winning player. Winning half your matches breaks even, assuming pack prices are 3 tickets each, and they are usually between 3 and 4, if not slightly above 4. That's why I said that any reasonably deck is good enough, since even if BR Blightning has a worse percentage than 5-CC, it doesn't have to hit that high a mark to be worth playing. One thing to be aware of is the pack payouts, as the value of packs varies wildly. At the moment, the 2-Man queus pay out a pack of Alara Reborn, which is only worth like 2 tix. With a 2 tix entry fee, playing for 2 tix makes absolutely no sense, so the 2-Mans should be avoided. Luckily, the 8-Mans are paying out M10, which is worth over 4 tix (I haven't been on for a few days, so if my pack prices are a little off, well, that's why).
The tournaments you want to be battling in are the bigger ones, as the entry fees stay the same but the prizes you can win increase dramatically. For example, take Daily Events vs 8-Mans. Both cost 6 tix to enter, but the prizes are better for a DE. If you go 3-1, you win 6 packs, and 4-0 gets 11. An 8-man pays out 5-3-2-2 to first, second, and 3-4th respectively. Your time is better spent playing in the bigger event (also, I don't really need anyone to chime in about how much more money you could make working / playing poker. I'm not suggesting anyone quit their job to play MTGO, but if you want to spend your time on the hobby that is Magic, you might as well do it in the most efficient way).
I tend to play in 8-Mans more than anything, simply due to time constraints, since they are way faster, but if you have the time to play out a Premier Event or Daily Event, they are worth it. Another benefit to bigger events is the caliber of the players. I prefer to play against better players, and anyone whose ultimate goal includes getting better should as well. Some of the bigger PE's are definitely close to GP-level competition, at the very least approximate to Day 1 of a random GP as you get to the later rounds. MTGO is a great learning tool, and part of the reason is that you have access to better players than those you can just find locally (not saying your local players are necessarily terrible, but having the access to a much larger and quite skilled player pool is awesome).
Anyone who claims that they are consistently winning product on MTGO via only drafting is exaggerating. I'm not saying that you can't go infinite with just drafts, but that it is really tough, and you rarely end up with more than just a few draft sets in the end. You have to aggressively sell all the rares you get, and a few bad drafts can wipe out any stores you have just like that.
Everyone is going to draft; I mean that is the reason we are playing Constructed anyways, to subsidize our drafts! If you look at it that way, you have the right mindset. Just treat drafts as a money sink and you should be fine. Drafting is awesome, and really the reason MTGO works, but don't look to them to provide product. The only exception is when a set first comes out, as singles sell for absurd amounts. Great Sable Stag is only worth a couple tix now, but I sold the one I rare-drafted in my first M10 draft video for 14 tix.
Sealed PE's are actually fine, even if just about strictly worse than Constructed ones. You can still do well just playing Sealed, but I would recommend you play Constructed when you have the option.
Build a Network
Much like in real life, playing online is much better when you have a good team / group of friends. Like I said before, I started along with my roommates Matt and Ryan, which made things much easier. We all had our own accounts, but we pooled our resources to buy decks and whatnot. This does take some trust, as I know tons of people who have been ripped of by their friends, but use good judgment and you should be fine. I haven't ever been scumbagged, and I lend cards to tons of people.
Having people you know online makes it so much easier to make decks, practice, and even just makes it more fun. Clans used to be awesome, although version 3 killing clan chat put a damper on that aspect of the game. Being able to borrow half a deck for a particular event is really awesome, as long as you occasionally lend out cards yourself. Nothing is more annoying than the dude on your buddy list who only messages you to borrow cards. Ultimately you will build up your collection to the point where you don't need to borrow much, but when starting out it is pretty nice.
That really is it, you should be in good shape to go infinite on MTGO now. Not everyone has a couple hundred dollars to spend on digital cards, but if you expect to be able to put time into online play, selling some of your real cards or saving a couple bucks a week in order to buy in online is worth it. MTGO offers access to good players, competitive tournaments, and drafts at any time, which is pretty unbelievable. The most common thing I tell people when they ask how to get better is "play online". Even if you just play an 8-man a few times a week while watching TV, you will get better.
Hello and Good Luck.
If anyone has additional questions or needs clarification, feel free to ask in the comments section, as there are surely things about MTGO I didn't get to here!