I launch and retrieve solo all the time. My procedure is the same regardless of whether I’ve got people with me.
1. Prep for launch away from the ramp in the staging area. Tie downs off, drain plugs in, gear and coolers on board, batteries connected and turned on, blower running, and lines set for easy access.
2. Back down the ramp and into the water until trailer fenders are just covered with water(that’s the ideal position for my trailer, yours may be different). Set parking brake and leave driver side window down.
3. Unhook safety chain, release the brake on the winch, let it roll off into the water, unhook the winch from the bow eye, and just hook the cable some where. You should be holding the bow line with one hand btw.
4. Once boat is free, hop up on the pier, walk it out to the end, tie it off, get back to the truck and get it parked. Walk back quickly, get in the boat and go.
The biggest hold ups I see at the ramp are people who wait to prep and load until they’re at the ramp.