I like fashion, and I like shopping, but I like being financially comfortable more! I am also a small wardrobe person. My trick is to divide shopping (catalogue on-line, bricks and mortar) into 2 types.
#1 is 'research' during which I recon the inventory and look at EVERYTHING. I do this ALOT. This gives me a sense of what is out there, what the prices are, how things are being styled and marketed. I don't put any pressure on myself to come home with a purchase, since that IS NOT the goal. Knowing the inventory well gives me a feeling of owning stuff, even if it is just the memory of where an item can be found. (That green midi skirt at Zara, those navy leather gloves at Danier, that black lace over bronze satin at Sears, the white on navy mariner T in LLBean, etc.). If I feel shopping fever coming on, I take a break or go home.
#2 is 'purchasing'. I bring a list, with pictures from magazines, or my iPad with Pins so I can show them to the SA's who want to help me. I wear good foundation garments and comfortable clothes that are easy to get in and out of. I put my blinders on, and I go to the places that I know will have the things I want to try on (because I've already done the 'research'). I stick with my list which might be quite specific - black pencil skirt, red turtleneck sweater...or more general - plaid shirt, floral print dress.
I've been doing a fair amount of 'research' recently, but purchases not-so-much in part due to buying and furnishing a new home, and being at a style crossroads. But, I find the approach I take ensures purchases are well thought out, and this in turn ensures wiser budget friendlier purchases.