Again, planning in advance is always a good idea. Here are a few tips on what to wear for great images. I change my backdrop out almost every year. You are always welcome to ask me what it looks like in advance so you can plan outfits.
1. Will Your Child Wear It?
Always pick an outfit that your child is excited to wear. It is hard to get a smile out of a kiddo that is uncomfortable or unhappy to be dressed in something they don't like. You may not want to give them full authority to pick whatever they want, but you can give them choice and let them be part of the process.
2. Dose It Fit?
This may sound like a no brainer, but seriously try the outfit on your child before coming in to see Santa. Too big is easier to deal with than too small, but for great pictures your child's clothes need to fit.
3. Pajamas VS Regular Clothes
This one is totally up to you! I love both ideas. I would stay with a Christmas theme with the pajamas if that is what you decide on.
4. Should My Kids Match?
Again, this is up to you. I would say that you do not have to match but if you have multiple children they should at least coordinate. You do not want one child in a Christmas t shirt and jeans and one all dressed up. Or only one out of three in a Christmas outfit.
5. Should We Be Dressed Up?
You are paying a little more to have a private Santa photo session, they are meant to be keepsakes for years to come, so my answer would be that although you don't have to be dressed up, you should pick something nice. Plan what the kids are going to wear same as you would for picture day at school.
6. Dress Yourself Too!
I cannot state this strongly enough! Please make sure you are picture ready also. You may not want a picture with Santa, and you may not be in the pictures but if you have a child who may be shy or scared of Santa it might be the only way to get a good picture. Better to be prepared. And of course I will always do a family picture with Santa if that is what you would like!