Several things to Sblargh:
First off, I wouldn't recommend drafting to try and get colors, just do it to win. It sounds like you want to do that solely to supplement your current "deck" but the thing is, you might find you enjoy how a certain color plays currently over say blue/black. Hell when I started playing my very first deck was green/white deck, then a blue/black, but my first actual "competitive" deck was Black/Green. Plus playing to win is more fun.
Next, assuming you decide to take my advice, remember this Acronym -
BREAD
B - Bombs. Simply put these are cards that can quite obviously change the course of a game. Really powerful creatures (usually not spells though occasionally they may be) that will put the game in your favor.
R - Removal. In limited removal is huge, since its harder to get reliably countered. So what if your opponent just dropped a 6/6 flyer with trample. You cast something like doom blade and its gone.
E - Efficient or Evasion. I've heard both and they're both valid. Efficient - Does this card provide a good effect and/or power/toughness for its mana cost. Does it work well with other cards you have, etc. Evasion - Can this creature get past other creatures easily? For example a 2/2 flyer may not seem like much, but when an opponent has no fliers of their own to block it, it adds up.
A - Aggro. Cards that tend to be cheap and incredibly efficient/powerful. Stuff like Reckless Waif, Stromkirk Noble, Elite Inquisitor, or Champion of the Parish (Just some random innistrad examples of the top of my head) are some great examples of powerful/efficient and aggressive early game creatures. Getting cards like this out in the early turns of the game can be big. Thats not to say that bigger creatures can't be quite aggressive as well, but don't forget about the early part of the game either.
D - Dregs, Duds, etc. - The crap cards you're left with.
When looking at cards make sure you ask yourself some questions - Will this fit with the cards I've already chosen, will this card be easy to cast (For example a 2RRRR card may look impressive, but may end up being a bit difficult to cast since you *usually* need to go two color in drafts), will this card save me in a tight spot, etc.
First off, I wouldn't recommend drafting to try and get colors, just do it to win. It sounds like you want to do that solely to supplement your current "deck" but the thing is, you might find you enjoy how a certain color plays currently over say blue/black. Hell when I started playing my very first deck was green/white deck, then a blue/black, but my first actual "competitive" deck was Black/Green. Plus playing to win is more fun.
Next, assuming you decide to take my advice, remember this Acronym -
BREAD
B - Bombs. Simply put these are cards that can quite obviously change the course of a game. Really powerful creatures (usually not spells though occasionally they may be) that will put the game in your favor.
R - Removal. In limited removal is huge, since its harder to get reliably countered. So what if your opponent just dropped a 6/6 flyer with trample. You cast something like doom blade and its gone.
E - Efficient or Evasion. I've heard both and they're both valid. Efficient - Does this card provide a good effect and/or power/toughness for its mana cost. Does it work well with other cards you have, etc. Evasion - Can this creature get past other creatures easily? For example a 2/2 flyer may not seem like much, but when an opponent has no fliers of their own to block it, it adds up.
A - Aggro. Cards that tend to be cheap and incredibly efficient/powerful. Stuff like Reckless Waif, Stromkirk Noble, Elite Inquisitor, or Champion of the Parish (Just some random innistrad examples of the top of my head) are some great examples of powerful/efficient and aggressive early game creatures. Getting cards like this out in the early turns of the game can be big. Thats not to say that bigger creatures can't be quite aggressive as well, but don't forget about the early part of the game either.
D - Dregs, Duds, etc. - The crap cards you're left with.
When looking at cards make sure you ask yourself some questions - Will this fit with the cards I've already chosen, will this card be easy to cast (For example a 2RRRR card may look impressive, but may end up being a bit difficult to cast since you *usually* need to go two color in drafts), will this card save me in a tight spot, etc.
