Fish trap made from Power Aide bottle works great.
Cut top off and invert it. Put some rock or sand inside to keep it down. Place in tank. Don't feed for a day. Place food in bottle on second day. Step away from the tank and watch.
Worked for two damsels, a bicolor psudo, and two clowns.
only downside is all the crabs and shrimp i caught on accindent.