• Went to army surplus store, got various stuff, also got peace buttons and a headband, took all my hair down (long hair), and wore the military gear all unbuttoned and disordered. There wasn't really a plan for the costume beyond that, but people partway through the night decided I was Ron Kovic, which seemed like it fit even though I had no wheelchair. I had a photo from that night for a while with a friend who was going into the navy, who was dressed up as some kind of special forces man with a big hunting knife, with us standing together him looking like a psychopath and me smiling doing a peace sign. We were the before and the after.
• The day I cut off my long hair, I invested in a super-sharp suit, and went before work to get it all cut off and get a super-sharp short hair haircut instead. I showed up to work in full suit and tie, neatly shaved, looking like a completely different person. My coworkers kept getting startled because they would look over at my desk and see this suit guy sitting there for some reason instead of me.
• When I was in my mid 40s I dressed up as an old man. Powder in the hair, glasses, old man clothes, and moved around all slow and careful and looked over my glasses at things. People were alarmed a little bit by how effective and accurate it was lol... like "I don't want to see you this way, stop stop doing that."

Those three I all enjoyed quite a lot.