Although I tutor people in several subjects, I really enjoy tutoring in French to Americans, because native English speakers who are learning French typically have the same difficulties with pronunciation, particularly, the ‘r’s. It’s not easy for us Americans to do, because we don’t have a sound like that. It's not easy to describe how to produce sounds, so one thing I encourage people to do is to get a teaspoon or two of water, tilt their head back, and gargle for a second, because the place where the water is in the back of your throat when you gargle is the same place you use when you pronounce the French ‘r’ correctly. Try it! You will be amazed at how easy it is.