AMN - A simple "No, thanks. I need to have it done a specific way. But I do need help changing my sheets. What are you doing Tuesdays." This way you'll let them know that you need it done a certain way but you are opening them up to the possibility of giving you the help that you really need.

I checked out plane tickets and although I would have absolutely no problem helping you on Tuesdays with your sheets, my budget and bank account has a HUGE problem with it.