Baby photo shoot ideas

We'll have a photographer come over this week and take photos of our eight months old son, but I've never had any photos professionally taken so do you have any ideas on what we can do? He can sit up by himself. We intend to give some photos as Christmas presents, but I don't think we'll do Christmas themed pictures, or do you think we should? Also, what do you recommend for him to wear? Should I dress him up in a plain suit or just regular colourful clothes? Please share your own pictures if you had a professional photo shoot done with your babies!