Not trying to seem paternal... but being not too far away from your age range and situation, my advice to you is to focus on the long term. Get your career going strong. Rather than strategizing about how you're going to maximize your FF miles, strategize how to take your salary from 30k to 60 or 80k in the next 5-10 years. That's going to take you more places than all the FF strategy in the world might do for you now.
The pursuit of miles and status can become a low-grade obsession and I'm not sure it's the best use of your time right now given your current income. When you find yourself with tens of thousands of dollars annually in CC expenses and/or a regular and consistent need to travel, then gaming this system starts to make more sense.
That all said, you might strategically look at opportunities to buy miles in unexpected ways. For example, when I was a few years older than you and in more or less the same financial situation, I took advantage of an opportunity to buy a few hundred magazine subscriptions and got ~300,000 miles on AA for it. It cost me about $2000 and was one of the better investments I've made. I used all of those miles to go to professional conferences and ramp up my career. Now the wife and I are spending enough on our credit cards that that spending is becoming a significant factor in our mileage earning.
Once you buy a house, you will get scads of credit card offers on favorable terms and you can start "churning" for miles. You do not want to do this until you have already purchased the place to live.
Summarizing my just-IMHO sanctimony:
+ grow your career
+ grow your salary
+ choose a mate carefully. It is the single most important choice for you happiness and prosperity. In a few years here, the good ms. fine will be able to buy me all the miles I could want
+ buy property, preferably a house
+ save for your Roth IRA first, and max out a 401/403b plan second
+ for now be on the lookout for opportunities that give you miles that won't distract you from the preceding stuff, which is bluntly a whole lot more important than mileage scheming.
+ keep reading FT, the advice here is gold.
When these ducks are in a row, you'll be well-positioned to join the rest of the loons on this board full-time, at least half of whom seem to pursue the miles thing as a kind of worldly hobby. Look around, there are a lot of very successful people here. For many here, it seems the financial rewards of their schemings are decidely secondary to their intangible enjoyment of travel and the pursuit of the good deal. Maybe a lesson to be had there.
Good luck! ^
-KF