Don't spend too much time on one game, because the game is already capped for you. And by now you should already have a firm grasp on which books offer the best lines, so shopping around shouldn't commandeer much time.

Time in sports betting, almost just as much if not more than anything else, is opportunity cost. Any effort exerted should be proportional to your implied payout.

All your data, or whatever method you choose to formulate a system of measuring statistics and numbers, should at its core triangulate around the spread and the betting market itself. If its not, then all you are setting out to do is to trying to beat the linesmakers, which is not a winning proposition. (Unless you are inclined to bet Swedish B-League soccer or some obscure sport/league where the market has yet to assert itself)

Find a way to stabilize your emotions, practice indifference. The emotional magnitude of a loss is 2.5x that of a gain, therefore some sort of purely objective and as one post said "sagacious laziness" has to play a part in your attitude and style.

The futures market can be a very useful convenience to invest in. Futures market when handled with a sharp sense of understanding and some obvious luck, can provide solid hedging opportunities, which breeds positive gains, guaranteed, from both a pecuniary and emotional standpoint.

In my opinion, one other thing is don't follow the games, emotion penetrates the entire enterprise when you see a horrible beat or dreadful luck play out in one of the games you put money on. Just quit following the sport you bet on, from a fan's perspective. The goal is pure objectivity.