Sometimes it’s easiest to flip the bike up on end – pretty easy to do with something like a StreetMachine. Not a problem if it has overseat steering of course.
Most two-wheelers, especially with underseat steering, will self-steer – you can just push the back of the seat. For tight manoeuvring, the CoG is around the handlebars, so you can just stand up and lift the bike by the bars.
Trikes pull well in reverse – pull it behind you by the rack.
I used to carry my trike through snowdrifts on my head – upside-down with my head on the seat, it balanced very well…