Back when I was taking lessons, I had an instructor who did a great job teaching me how to work tapping into my bass lines, but when we tried to expand it into developing slap bass I ended up getting hung on the mechanics, and couldn't work it in fluently. Are there any exercises I can use to get accustomed to proper form when slapping?
This may sound silly, but it really worked for me: Whenever I was sitting down, I practiced bouncing my right thumb off of my right kneecap. I was going for a real bounce, not a whack (that hurt). At school, on the bus, watching TV---I practiced my slap technique all the time, even when I wasn't anywhere near my bass. Goofy, sure, but totally effective.
The trick to this, and any technique when starting is: practice slow.
Not the answer people like hearing, but there are studies that show that the way we learn is not dependent on speed, the pathways in our brain are linked up (which is what "learning" is on a chemical level) even if we repeat something slowly over and over. Read about how one of the most famous classical music camp shows kids how to practice slow here - http://thetalentcode.com/2009/03/30/meadowmount/
Also the trick to slap is the note that doesnt make a pitch, but is just a click or a percussive note. So there are three components:
You have to get all three happening to get slap going.