I shop online. It's $9 for delivery but I'd easily spend more than that in impulse buys.
When I did go in person, I used to have a limit of allowed impulse buys - 3 or so. That allowed for the thing I knew I needed but had forgotten to put on the list.

With hobbies like video games (probably can be applied to other things) - you can't buy something without selling something. If you want a video game, you have to sell one you already have to offset the cost.

Budget in pocket money for everyone. For everything. Even a clothes budget separate to personal pocket money. When we have pocket money, we think 'okay only 2 more weeks til I can get that', as opposed to thinking 'hmm haven't gotten anything in awhile, I think I'm due for something', but losing track of what you've bought in the past. Works really well.