Night time sneak attack with a red lens on a flashlight. I use ninja stealth, and if that doesnt work turn on all the lights and go for the flash bang effect. usually they are so traumatized I can easily catch them, some even jump out and surrender.
Or just chase em to exasution and then net em ..
Ive heard mini spear guns can be made, but im afriad to hurt a coral.
Seriously trap em is best imo.
Good luck,'
Chris