The largest net you can get will reduce stress as they are easier to net. If your constantly chasing a fish around with a small net you'll increase stress and likelihood of injury.
just get a large net, put it in your tank for a bit, after the fish are used to it slowly net the fish. don't just thrash about wildly trying to catch one fish (although this is hilarious to watch especially in larger tanks)
I don't know if anyone has tried this or looks down on it - but I have a large clear pitcher that i use because using a net really didn't work for me plus I thought it put undue stress on them.
They seem to just swim into the pitcher and they don't get caught on the net they just slip out of the pitcher.