Whoever you are working with for the mark and recapture should be able to point you in the right direction. What method of marking etc are you using?

Use the proper tools, remember that if you are in strike range, the snake can always win. Just because it didn't bite you when you slipped up last time doesn't mean that it won't ignore you the next time you are within strike range. Honestly, runny copperheads in the 2 ft range can be a royal pain to work with in the field at times.

And the advice that was given to me years ago: Keep your fingers out of their mouths! (Thanks Randal!)