I would ask that anything I help create could be used in my personal portfolio, body of work and website. However, if this is problematic, then tell me and I will be sure not to include anything that is requested.
I would also ask that I be given sufficient credit if you decide to post my artwork online in some capacity.

I usually start with an initial rough sketch to show how the piece will look. Once you approve of the direction of the piece and how everything looks, that is when payment is required to finish the project. I will be willing to fix any minor mistakes for free however major fixes will require an extra payment if you need.