I understand the buddy system issue. It's good to have the second brain, the person who could render aid or go for help. When solo you have to find ways to adapt.

My solo trips aren't much different from trips I take with others. I will do off trail routes, though I map them out carefully and leave marked maps behind. Other than that, I mostly second everything Lori said.

I would add them when I find myself confused, scary, thinking something is risky, I have found the best thing to do is STOP. Don't let emotions / fears drive you. For example, if it's dark and you are having trouble navigating (can happen to the most experienced folks), consider sleeping where you are and figure things out in the morning when you have light and are rested.

I think a Sat Phone or even better, a real PLB (not a spot) can address most of the really scary issues of solo except an even which results in your suddenly being rendered unconscience and never waking.

--mark