On doing your own thing in a workshop
Cloning is very common with some art instructors. Often students think they would like to paint like a certain artist, and that's why they choose him or her as their instructor. Some instructors encourage this; it is very flattering. Thus, the more the student's work looks like the instructor's, the more affirmation the instructor gets. This is one of the reasons most exhibitions have a rule disallowing any work done in a workshop.
I've seen instructors get annoyed with students who try to "do their own thing" in a workshop. The attitude is, "If you don't want to do what I do, why are you here?" To some extent, they have a point. Perhaps you should pay attention and do what the instructor is doing instead of what you already know how to do. You will--I promise you--learn some worthwhile things in the workshop, even if it happens to be what you don't want to do. You'll learn some new tricks with brushes and paint that you can apply later in your own work. You might learn something new about design and color, too.
It isn't the purpose of a workshop to produce paintings to show and sell. It's to learn what a certain teacher can teach you. I have a slightly different take on weekly classes, though, as I feel in that situation it's the job of the teacher to help the student become the artist each one is capable of being, and not a clone. So it boils down to finding the right instructor who will work with you to bring out your best and help you overcome your weaknesses.
Read my web site article, Ten Tips on Taking a Workshop for more thoughts on workshops.
Next week I'm taking my third workshop this year. I've been so out of painting with all the baby-sitting the past three years that I'm trying to get myself revved up again. I took from Judi Betts, whose style is very distinctive and different from mine, but I did all the exercises everyone else did. I took oil painting from Charles Gruppe and the only way I departed from his method was to paint a cemetery and the desert instead of boats in New England. (He couldn't imagine why anyone would want to paint such things!) The next one is with Donna Zagotta in watercolor. I don't know what to expect but have been told she's a good teacher and I know I'm a good student, so I will learn from her.