I normally have 2 nets.
One white meshed and one black meshed, both sort of medium sized.
I find the fish can see the white meshed one far more easily and shies away from that one then I use the black net to sneakily close the door behind on them and hey presto, fish in net (usually!

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This works pretty well for me.
Also find that using larger nets is a pain for me as I keep getting that net snagged in wood / decor or plants and suchlike making it easy for fish to escape, so try ensure have a net that’s not too small that makes it easy to miss your fish target but not too big so it gets caught in everything in the tank!
Oh, and lowering the tank water helps as well so this give less escape room for the fish to get to.