Dwelling on purchases is better than being an impulse buyer but I think the balance is somewhere in-between, closer to the former.
I've got friends and family who'll walk into a store like Curry's and just choose a TV based on what it looks like. Then they'll complain it has issues which turn out to be things like ghosting, motion problems and grey blacks etc.
My purchase decisions goes something like this.
Step 1 - Want something
Step 2 - Then ask the question is it something I want or is it something I actually need.
Step 3 - If it's something I want then I wait a week, see if the feeling of GAS is there, or even a month. Most of the time if I can get over that initial WANT phase, l will forget and don't miss not getting it, and no regret either. I started doing that last few years and it has probably saved me loads of money. If I find myself 6 months or something later still thinking about it then I will get it. It has passed my test of time.
Step 4 - If it's something I need then I move to the next step
Step 5 - Research, depending on the item. Sometimes a trip to TK Maxx will do, water bottle, chopping board or even a saucepan. I kinda already know what I want and the kind of quality I am looking for.
If it's something I have no idea in, like say getting a new Microphone then I watch an evening of YouTube video, at the end of it I will get an idea of the market. It also means I seldom end up with something off Aliexpress or cheap Amazon seller because the reviews and videos will give me a shortlist of items and I would be looking for named items, not generic item names.
5 Steps, don't really return anything, a few YouTube videos save me lots of returning time and effort.