Oil paints and acrylic paint are the two mediums that if you do not like the work you have done give you the opportunity to change them. Oil paints and acrylic paint are the two mediums that if you do not like the work you have done give you the opportunity to change them. You could either paint over them or repaint you piece after it dries. Pastels are not forgiving but it is the best way to learn to paint in oils. You can learn color combinations and what works when sitting your colors side by side or layering them. Pastels where Degas love, he was wonderful in his renderings of side-by-side colors. Take a very close look at his pastels and you will see how he placed one color next to the other color and made his pieces dance. The old masters used pastel as groundwork for the oil paintings later. I am a big believer if you want to work in pastels that you buy the best pastels you could afford. There is a very big difference in color and how the pastel adheres to paper. Please be very mindful of the choice of paper as well. Something with some “tooth” to it will hold the colors better than apiece of very soft paper. The weight of the paper is subjective and some chose one and some chose another that is your choice. But if starting out buy paper that is reasonable in price and remember to save your pieces so you can look back and see the progress you have made. While you are at it purchase a fixative for the pastels, it holds the color. One thing you could also do is spray the piece and you can still use the pastels over the spray and spray again, do not saturate the paper, just a light spray will do, and see what happens. Try not to smug the paper with your fingers, your fingers contain oil and that oil works against you when using pastels. If you want to work the colors together to make and oil painting effect, try using a pointed cardboard cylinder that you can purchase at the art store, it works, and just remember to clean it off with a cloth after you use it each it so the colors you use do not transfer to the new place you are working on. Pastels do not mix like oil or acrylics; they are a medium all there own.