One of the best skills you can have is to learn how to tie a rappel seat or a Swiss seat.
Being able to do a basic rappel can be a very powerful tool in your skills box.
In the rugged wilderness a water crossing can be a real challenge, it can be made easier using a poncho raft skill.
A flip flop winch can be a very powerful technique when you have limited resources.
Knowing some basic knots is also very helpful.