If you're running something like test which can cause gyno to those that are prone, alot of users like to run Nolva at doses ranging from 10-30mg throughout to keep gyno from occuring.
You can also choose to use it AFTER your cycle. In that case, I would run your PCT at:
Wk 1-2 hcg 1000i.u E3D
wk 1-6 Nolva 25mg ED
wk 3-6 clomid 50mg ED