Height wise - I just don't stack up to Lynette.
She's 5'10 and I'm 5'5 (on a good day.) So to make sure I don't look like a troll and she doesn't look like a giant - I need to take some special measures. Each morning I build my seat up so we look closer in height to you on TV.
First, I put a phone book on the chair. It is wrapped in heavy tape so the pages can't slide.

Next I add a red pillow.

Then sometimes I'll top it off with a black cushion for added comfort.

Because if I don't stack myself behind the desk....then Lynette and I would look like this...pretty awkward.

Also in some shoots, I've stood on boxes and walked on big seat cushions. But this is all better than my last job. There I had to sit on a sandbag - not comfy at all. The lengths I go to get the height I need!