The biggest solo tip I can think of regards solo sit-down dining. For my first 4 trips, I just couldn't be comfortable with sit-down dining. Then I tried bringing a little notebook and pen with me, and using the time to jot notes to myself on where I'd been, impressions, what I'd eaten, where I wanted to go, etc. As a little side note: it was funny one time at Norway-I guess the server thought I was an undercover reviewer working for Disney, making notes on everything. So I got excellent service!
The other tip I can think of offhand is "if you see a chair and want to sit, go for it! Want to ride that train just pulling into the station? Go ahead!" I remember one night walking along the Boardwalk and the Friendship boat came along. I suddenly realized "Hey, I've never ridden the boat at night", so over to the dock I went. What was funny was that the CM was going down the line to see where everyone was going, so he'd know where to stop. When he got to me "Where are you going?" "For a ride on the boat!" Everyone laughed-you don't always have to plan in Disney.