Hello Forum!!

I strip then use needle nose pliers to put a sharp U in the wire. Then I hook it into the socket then smash it with the pliers. The idea is to get a good mechanical bond before you solder. I have a factory wired Dynaco. One day I was looking at it and noticed that one of the wires had never been soldered. It had worked for 50 years solely from the mechanical bond without a problem. Of course you don't bend wires on the circuit board but I hope everyone already knows this.
As far as wire goes. If the wires are from a transformer or choke the I leave them a little long just in case I need to trim a little off in the future. However all hookup wires should be sized and fitted without excess. If you cut it to short or some other problem just cut another wire and keep that piece if it long enough for another location.

Crimping can damage the tabs ... the metal is springy so it'll grip the tube pins tightly, which makes it a bit brittle. Also can be a PITA if you ever have to make any changes.

I just let the solder do the work. Pre-tin the socket tab, pre-tin the wire, clamp the wire to the tab with hemostats, and flow enough solder to fill the hole and give a good transition to the wire either side of the tab. The hemostats provide a heat sink so you don't melt the insulation while you're making the connection. Trim the excess wire off even with the solder and then bend the wire so it's pretty.