One thing that can surprisingly help during normal play is to just verbally say to yourself "Too Early" or "Too Late" when you take a shot that doesn't make it. Eventually you'll start to "feel" the reaction of being too early or late on your shots before you even finish pushing in the flipper button. If you can't tell if it was too early or late by the way it bricks out, just guess. Your guesses won't always be right but at least you're telling yourself that you're doing something wrong all the same and making your brain think about it more. Sometimes it can also help to just try the shot from the other flipper. Sometimes a shot is easier to backhand than forehand. : o
If you find yourself bricking the same shot over and over no matter what, just skip it and go for other shots. Usually there's more than one way to score big on a table, especially if it uses a DMD instead of an alpha-numeric display. For instance, on T2, if you have trouble hitting the lock shot, just go for ramps and loops instead. Left loop can award a lot of good stuff and alternating the ramps enough will get you Payback Time where every major shot is worth 5,000,000! If you can find and repeat the right-loop over and over you can not only get it up to the 5,000,000 value itself, but unlimited millions on top of that!
Practice ultimately makes perfect of course and I think Stern's notion of having its employees play at least a little pinball every day is a good one in that regards. If you wanna get better, get at least a few minutes of play in every day! : )