The coke bottle trick has always worked wonders for me. It helps to not feed the tank for a day or two before and to use a piece of meaty food.
Funny part about the trick is that i used it at my LFS
. They had a really nice dartfish they just couldn't catch in a tank full of LR
. I was talking to the owner of the store about it and he said they even had it on reserve for someone. In the event they got it caught they were to call him so he could come pick it up. I told the owner i could catch it and he bet me 25% off my next fish purchase that i couldn't. I walked across the street, bought a bottle of water from the mini-mart, drank it down, whipped out my pocket knife and walked outta the store with a 25% off voucher for when i start to stock my tank.