There's two diff issues at play here I think. The first being a general mythology about touching fish, which Hemingway wrote about in a short story even. When you are doing catch and release fishing for sport you are supposed to never touch a fish with bare hands, or dry hands, etc. The idea being that you will leave a gap in their immunity where infection can set it. Poppa wrote about finding healthy fish dead with fingerprints on their sides.
The second is more pertinent. When you trap a fish in a net it goes batshit. That's not good for the fish, because it's scales and fins can snag on the fabric and tear off. So you have a site primed for infection and a stressed patient, not a good combo.
This will all be much easier if you remove almost all the water from the tank. Leave them like 4" of water to run from you in.
For larger fish I like to gently scoop them in my hands. I tease them close with tasty food and then sort of trap them against the glass and slide them up to the surface. If you do it carefully and with patience they kindve submit. For littler fish a colander is a good option, or any old takeout container or Tupperware with holes poked in it (smaller than the fish obvi).
Maybe it goes without saying, but if there isn't a concern about transferring water, just scoop him up and dump him where he needs to be. Usually when people ask these questions they're fighting a disease and trying to minimize the water transferred. If you're just upgrading tanks or something, use like a lemonade pitcher. The fish won't know what hit them if the salinity, temp, and alk are matched. Rig a trap door on it and feed them in there for 2 days. Then on day three, drop the hatch, scoop them up, and dump them in their new home.
