This may sound cowardly, but I've found it to be good advice: Don't be afraid to run!
With many modern RPGs that I've played there is a general organization to the game that usually doesn't present you with anything too difficult for you to handle given your current level in the game, unless of course you're stupid enough to wander into places you clearly shouldn't be.
Conversely, some older roguelikes (like Nethack) can often randomly present you with creatures that are vastly beyond your current level or abilities. After playing many modern "balanced" games, you may think that anything you come across can be defeated with a little strategy, but this is probably not the right attitude to have for some of the games you listed. You have to keep in mind that at any given moment there is a non-zero chance that you could run into a very tough enemy. And flight is your friend in such a case.