How do I shave my mustache and beard without making a mess of the sink?

This is what you want. It works great. I’ve owned several over the years.

Unfold a newspaper over the sink

The weather is really nice. Grab an extension cord and head for the porch or backyard.

I wet-shave, and I do it in the shower.

My fiancé shaves in the shower. We got a suction-cup mounted mirror. He also buzzes his own hair in the shower (before turning the water on) so all the clippings wash down the drain, I get the back of his neck for him.

I use paper towels, and toss in the garbage when finished. Don’t flush down the toilet.