exercise in alternating effect

If its a book about "'all about techniques in acrylics', then I don't think there is a problem. You are expected to use the techniques, and yes copy why not. Just don't try to sell it as your own original art. But then again, use the techniques learned to create something original? As it is, not a bad painting. Only thing I might suggest is a little dark reflection/shadow under the foremost hill, as it appears to be floating on air?

I agree with Tony's comments, but do like your use of colour. You are certainly becoming a versatile artist. Keep at it.

Thank you, both. That is reasssuring. And thank you for your help with the floating hill. It certainly didn't look like that in the book! I will go and try your ideas right now. Please keep the suggestions coming. They are most gratefully received and are, I think, a strength of this website.

This is the only picture I have here that is not totally original. I feel a bit uneasy about it and may eventually delete it but for the moment will keep it to help me see if I am making progress.