Nice thread as I've been wondering what others do whilst waiting. Here's what I do;
1. Sit and observe what's around me. I love seeing so many Teslas in one place, and I'm willing to talk to other owners if they're up for it.
2. Read the news on my phone and lately, TMC (especially the Investor's Roundtable thread).
3. Relax and watch how fast my local 250 Kw charger fills up the battery (especially when in a lower SoC).
4. Grab a coffee
5. Pinch myself because I finally have my Model 3 and I'm Supercharging!