This was the guideline that I read somewhere (maybe the trailrunning reddit) when I started getting more serious about hills: wear a hat with a brim (i.e., baseball cap - or imagine you're wearing one). If you can't see the top of the hill because your brim cuts it off, then it's either too long or too steep to run up it, so power walk. If you CAN see the top of the hill beneath the brim, then try to easy run up it. Obviously, this guideline depends a lot on the T+D and how tired you are, etc., but it helps you start thinking about judging when to run and when to walk.
I still keep this in mind for trying to keep my expectations reasonable.
I honestly just this past 6 months when I was training hard for a very hilly race got up to the point of being able to easy run hills of like 3 - 5%. If they are any length, the effort adds up quickly.
It's tough to take in typical advice that you read in different places about trail running because so many folks are just much faster runners and don't realize it. They are still walking steep hills (really, everyone does, even the elites), but for shallower gradients, they don't realize how difficult it is for slower runners. On a 5% grade hill, they might go from a 9 min/mile to 12 min/mile and still make good progress - but they make a big deal about how they have to go so slow (it's true for them!). But those of us that easy run at 13 min/mile then get slowed down to a brisk walk even at the smallest hills.
There's nothing WRONG with that, but it means that when you read about what others may do or suggest, you have to take it with a big grain of salt.
