I do!!! Unfortunately SA tend to actually judge u on what u're wearing.. so when i go to Chanel.. i usually wear Chanel jacket/boots.. and when i go to LV i wear LV jacket/LE bag.. etc!!
IMO, ive found out that the SA'S will talk to you more if you have your lv bag on.... (when my mom goes to the boutique, all the Sa's are cooing over her bag ...even if its a speedy...lol!)....anyways, i do try to dress up as much as I can...