Keep in mind the first few days of the season very bad bidding wars. A great time to sell, not so much to buy. I like to pick up the roles I need with young players on the verge of their next star, and hold them there till the next season. The best times are very late at night or very early morning, when less people are on. You might also look for multi-role players that aren't too old. Defenders seem better lasting age wise. Since you get no free token, you have to avoid bidding war, but if you see a player you want "+" him to your favorites and you can see if people are bidding on him.

Look for free agents throughout the whole season. If you leave one slot free you can get great deals. Play them a few games, if you like their performance, keep. Or sell for profit.

Anyone at 26 or over should be examined, look at their ratings, and how often have then been injured.

Look at the ratings and stats, compare your players and see who isn't performing... consider selling anyone other than a keeper that has lots of 5's.