Don't stand up. Or at the very most, only if you are on a really long one and you need to stretch. Standing is less efficient. I just have standard double with 11-28 in the back and I live in the burbs of SLC. I sit and grind. I am never sure of the point of standing when the climbs are all so long. Long steep climbs just need endurance and practise, not gymnastics. I don't think though, that I am getting much bigger grades than 16% (fleeting). I would stand rather than fall, but that would be it. Because I don't have a granny or a compact, I probably mash a bit more than is desirable but I really like to climb, which is a requirement in the Wasatch. I am old and not racing though.