As my DH is at the shop more than I am, he seems to do a lot of the ordering. I usually just pay the bills and do the paperwork. At the end of each month we know how much we have left in the bank and that is when I can buy things I want. I also have a wish list which I refer to at this time. If I still want something after it has been on the list for a month, I get it. It saves on impulse buying, which I used to do a lot then regret.
Clothes, shoes etc are allowable at anytime.