watch replays, lots of replays. Look for not just the obvious horse sitting in the two hole that got locked, everyone saw that. Look for the horse third or fourth under that with the help of the program is going to get some money off the card and make a drop in class in next start.
I'm big also on watching the fractional times. It's one thing to watch a horse close 8 lengths when the second half of a mile is slow.... It's another to see a horse close, even slightly running wide after a slow front half.
I will watch 20 replays and try to find one or two horses.