Make sure your ticket is correct before you leave the window.
Bet on horses that have won some races before.
Avoid betting on a horse that has recently moved up in class. He may be out of his league.
Bet on a horse that has a pretty good chance of winning but is not bet on too heavily.
Don't waste time on races where the favorite looks tough.
Avoid horses that are hyped. Horses that are heavily favored to win will win more often that most horse but you will not win enough to justify betting on them.
Make value bets and not just bets that are most likely to win.
A track that is slow or heavy benefits horses that take the early lead so in these conditions you should bet on the horses that are fast starters.
Be selective with your bets. Don't bet on every race.
If a heavily-backed horse has his odds sharply reduced just a few minutes before the start of the race then bet on it. This indicates that somebody has favorable information about the horse that nobody else has.
Give preference to a horse if it has run recently. A horse that has not raced for a few weeks may have suffered a setback like an illness or injury.
Give preference to an experienced jockey on longer distance races (over a mile). The longer a race is, the more a jockey's talent matters because an experienced jockey is better able to properly gauge the pace of a race.
If there are several horses in the race that want to take the lead then there will probably be a hot pace. This may sap the energy of the early leaders and give the the "closers" an advantage. Conversely, if there is only one horse that wants to lead, he is very likely to seize the lead and coast along at a slow pace, conserving energy to fight off the stalkers at the end of the race.