I approach football handicapping much the same way I would any other sport, but there is far more work that needs to be done to prepare. It is necessary to know the rosters of each team and especially in the NFL, that is a constantly changing aspect of the game.
I'd say one thing I like to do is play "off the grid" games and conferences. It allows me the opportunity to catch a better line at times. Everybody focuses on the Florida State like teams and much is written that even the casual fan is aware of. Going to Conference USA or the MAC is what I like to do. That doesn't mean I won't play Ohio State, but I'm less likely to play a top ten match up.
It is crucial to keep up on injuries. I like to focus on who is injured on the offensive and defensive lines. That's where the game is played. Give an average quarterback a great offensive line and he will suddenly be better. Give a great quarterback a porous offensive line and suddenly he isn't as effective.
In games where the spread is small, you must focus on the kicking game. That includes, especially in NCAA, kick offs and punts because that is where field position is determined. Obviously a kicker who is nearly automatic inside the 40 is a good thing. It amazes me that many top NCAA teams have horrible punters and field goal kickers. They often make the difference between a win and a loss.
I like to play the money line in many cases. Many people will balk at laying a big money line number, but you wouldn't hesitate to lay -240 with Kershaw or Arrieta on the mound. Nor would you back off from laying -300 or more in a boxing match or a UFC fight. Especially at the beginning of the season, when there are still question marks, this is a strategy I am comfortable with. I also like to use the money line play when the line is small, like 1.5 or 2. I will use the money line there with favorite or with a dog.
Probably the main thing I do, and others have mentioned the same thing, I like to make my own lines. I will craft my own line before I even look at the Vegas or Offshore lines. It enables me to immediately discern where I perceive value. I'm generally pretty close to the released line, but if I see a big difference it alerts me to the fact that I either have a bargain or that maybe I missed something.
You have to differentiate between college and pros, but a final thing I like to do is read the local papers on line, especially for the colleges. You can gain good information and get a better feel for what is going on with the teams. The local papers also tend to be critical at times which is also good to know. There is an abundance of information there. So skip USA today and go right to the source. Local papers are always available on-line.
I also make use of video. I have multiple screens set up to watch and record games - focusing on the games I bet if possible. This will make it clear to me what I got right and what I got wrong. This is an ultimate time consuming job, but seeing it rather than reading about it helps immensely.
I hope this helps you have a winning football season. I have read all the info here and it is very solid. Pick out some of the things that you have the time to do and you will see an immediate improvement in your handicapping.
Good luck in 2015!