1. Always go clothes shopping in your favorite outfit.
2. When trying on clothes, only buy if all the following apply:
a. You LOVE it - that means heart racing.
b. You can wear it (top, bottom, or entire outfit) with what you are currently wearing, and you want it wear it straight away.
c. To really test this, always ask to wear the new item(s) straight away.
Trust me, the only clothes I hardly wear are the ones I didn't ask to wear out of the shop. Makes me nuts looking at them wasting away in my closet!
Also, you will find since you love that new jacket so much, you won't even want to buy a second or third one for a very long time.
This is great for people who are overwhelmed by choosing, because there is no pressure to find a lot of items. If you just find that one dream skirt, then you've done great.
This can work for formal wear also, in case you are thinking, hey, I can't wear that formal dress out of the store in the middle of the day! Imagine you need to go to a special event - don't freak out and think you need a whole new expensive wardrobe. You can buy just one piece (jacket or shirt or bottom or boots for example) to add to existing daywear outfit that is more sexy, glamourous or sparkly perhaps (ladies).
What I often do is add shiny boots and special earings to an existing outfit and it's never underdressed.
There's nothing more frustrating that having a closet with 80% clothes you never wear!