I've used MyTopo quite a bit. I find 1:24000 to 1:30000 scale to be the most useful.
For me, I spend alot of time on Google Earth in 3d looking at vegetation in relation to topography then compare what I'm seeing to a paper topo map. I tend to take/keep notes on the paper topo map and have it in my pack. I whip out the paper map a bunch during mid-day and compare to where my GPS says I'm at. I always have a game plan when I move around. The way I do maps helps me develop a game plan before I move and helps when I'm changing the plan on the fly. It's pretty tough to recall vegetation and topo correlations while you're out in the field. Some of the newer phone apps work but they don't work in some situations. The paper notes/map works under all circumstances.
