Step $1$:

Look back over some recent writing you have done $($for this class, another class, or for work$)$ and find some sentences to work with. Select ten sentences from anything you have written $($all ten do not have to be from the same document$).$ As you search for and select sentences, you are just looking for any sentence. The point isn't to find a sentence with an error$--$the point is just to pick any sentence $($perhaps even a really solid one$)$ and find ways to improve it$.$