I normally recommend that people wear their boots around the house a few times before going skiing.
The two main reasons are:
1. To get their feet used to being in boots.
2. To make sure there aren't any niggles/pains that they didn't notice when in the shop.
surefoot told me to wait on wearing my new boots around the house ect. until I get my custom footbeds because the liner will conform to my foot & it may be different with the new footbeds. bteddy waiting on feb 1st
The problem with wearing your boots around the house is you are not in the same position/movements as when you are skiing so the liners if they do get some forming will not be proper. Get to a good fitter and work with them. The other option is to put some skis done on the carpet and step in. then work your boots like you were skiing. (with poles for balance in front of the TV?)
Walking, sitting, whatever will only point out the problem with that boot for when you are walking and sitting..