@theduchessofspork when it comes to clothes I have several things in place as well.
Three things that work for me (most of the time).
Never ever shop for a full wardrobe at once. One outfit at most , few pieces at a time staggered out throughout the year.
I have my clothes split into work clothes (boring, practical,don't need too much thinking about) , me clothes (this is where I can have a bit of fun and experiment, if they're good for work too, that's a bonus) , house clothes (comfort wins here , and my old me clothes get downgraded to house clothes when they're not great).
Cheat hack. If I'm not sure about something or want to experiment I go on ebay ( I guess Vinted is the trendy app now) and look for the item in my size and add to watch list. If it's buy it now I leave it there for a few weeks, if I don't actually want it I found that I forget about it or when I return to it I lost interest/I have doubts. If i still love it, I buy it. Same for auction, and if I can actually make the effort to check on it,bid , remember when it's due etc. that means I really want it. As an added bonus I can try a lot of things cheaper and if it doesn't work it doesn't work. I donate them or give them to friends or if really awful just bin. If I'm happy with it THEN I can look for the same thing or similar in shops.
In real shops I set myself a number of items rather than a budget . This doesn't stop me picking up everything, but it does stop me buying it all because I have to pick the bits I want the most out of the pile. And the usual questions do I need it, do I love it, will I wear it , does it make me smile/happy? 3 yes's it's a go.