But, back to the homework.
I think everyone took home a photo yesterday, but I'll insert a couple more here for reference.
The sky in the image above looks all soft-edged to me. I'd start by wetting the paper. That first wetting, remember, should be wet enough to provide all the water for the ensuing layers. Guess who's in charge of this. I'd quickly follow with a pale yellow-orange wash along the bottom of the sky. Then I'd add pigment to the brush (without rinsing it off first) to make the light gray clouds I see near the horizon. Finally, I'd add more pigment to the brush to make all the darker clouds.
Take a look at the ground in this photo. Would that be a candidate for a wet into wet treatment? Try it, if you're interested. It may be that this is suited to a wet on wet treatment only part way through the sequence of layers, after which some hard edges may be required.
This is an exercise, meant to encourage practicing technique. The goal is to gain some confidence about producing the kind of edges you want. The goal is not to produce a handsome painting. The pressure that usually comes along with that goal is liable to constrain your brushwork, and tempt you to correct whatever isn't accurate. The more you do either of those, the less likely you are to make a natural looking interpretation. A couple of scraps of paper with patches of sky or sagebrush would be more appropriate than something ready to frame.
How many layers do you see, moving from light to dark, in the water? Would you wet the paper first or leave it dry? Not sure? Try it one way or the other. The study will reveal the answer. If your choice was not ideal, don't fix the study. Make another one, instead. And bring them both to class!