On the Cycleops trainer I always wear a wicking fabric t-shirt, bandana around my forehead, and keep a towel nearby to wipe my face, hands, forearms, etc. And I have a tall oscillating fan running. Feels more comfortable when the sweat evaporates rather than dripping down my torso.
It doesn't feel like I'm sweating much but I'll go through a 24 oz bottle of water per hour and the towel will be soaked. Good evaporation makes it much less uncomfortable.
Ditto, avoiding letting sweat sit on the bike, especially the bottom bracket, stem, top tube, etc. I've seen some otherwise good bikes ruined that way. You can always tell when someone's older classic steel bike or their first aluminum or carbon bike was relegated to trainer duty. Many folks neglect routine wipe downs and it shows.
OTOH, my worst habit is washing my outdoor bikes only once a year, whether they need it or not. Hey, that 30 minutes could have been spent riding. I'll regularly maintain the drivetrain -- clean chain, chainrings, freewheel/cassette -- but I tend to ignore the frame until someone scowls at my bike or says something.