When I go overseas I usually use the opportunity to shop for things we don't have in Australia (particularly true before Uniqlo opened here). I have come back with sizeable hauls in the past, e.g. my first time in the US. The downside is that a lot of my regret buys have also happened while travelling - most likely because I don't really get the time to "think about it" if I'm somewhere temporarily. This time, I set out a mental shopping list for myself before I left, which definitely helped curb the amount I bought.
I picked out these Cole Haan loafers online before I left Australia. My Bass loafers were due their second re-sole, but there have always been little details about them I didn't like - they're patent, just a tad pinchy in the toes, and they have slippery leather soles which wear out quickly. I decided to cut my losses and replace them. I like that these have rubber soles which should provide better grip on hospital floors (it's hard to walk confidently when you're afraid of stacking it) and also last longer before they need to be re-soled. The leather is quite stiff, but felt a lot softer on the display models, so I assume that will come with wear. They do make my feet (already too big for my body) look hilariously long, but what can you do.
Otherwise, I only bought small things out of necessity - a pair of socks (somehow all the socks I'd packed started shrinking and slipping down my heel which always makes me irrationally angry), facial cleanser as I'd run out, and acne treatment. I did have trouble walking away from some tops while browsing thrift stores in NYC (seriously the thrift stores there are so much better than ours). I'm pretty proud of myself for sticking to my list!
The other things I'd been on the lookout for were a navy/white breton top as a replacement for my current one, a blazer or suit set, and a leather handbag that can fit a laptop/A4 documents. Nothing caught my fancy in these categories, but none are urgent so I'll just sit on those for a while.