If you are a beginner and are trying to learn some tricks here are some tips to avoid pain and succeed:
1. Never hold the bite (latch) handle. This will end up with your hand being cut.
2. Tape up the edge with scotch tape or painters tape as it will leave no residue and also prevent any cuts while you're practicing.
3. Always keep practicing because no matter how hard the trick is, if you practice enough, you'll get it.
4. After a while you'll realize that the harder you snap the knife back and forth, your fingers will bruise because of the latches / dull edge hitting against you so don't be so forceful when you practice.
5. When you begin to learn moves that require momentum itself instead of your own power all the time such as around the eightball, don't be scared and just do it. If you're afraid of getting cut refer back to number 2.