In the vast majority of cases, the simulator sets the random tape of the adversary simply because it has to (by the definition). So, the simulator sets it in the beginning to be uniform, and this is then ignored from then on.
There is one cases that I know of that this is actually really important, and this is non-black-box zero knowledge. Specifically, in Boaz Barak's thesis, he has a number of constructions. The construction which works for uniform verifiers has the property that the verifier has to have a short description. In order to make this work, the random tape of the verifier is actually chosen by the simulator pseudorandomly (rather than truly randomly) since this then has a short description.
I don't know of anywhere else that this is important. In general, choose it at random and ignore from then on...