I feel like the biggest thing that helped me was learning about clothing construction and materials. A lot of stores tend to have hidden gems that can be constructed very well and made with quality materials. Things I tend to look for are a good lining in dresses and jackets, natural materials or blends at least, taking a good look at the stitching work and how sturdy the seams feel (give it a delicate pull if in person and see how the threads in the seams hold up), how thick a material is, etc. I've found a lot of really nice stretch silk blend shirts at thrift store in great condition that have become staples.

Another thing I've discovered on a budget is that good quality syntehtic products exist. I usually only buy skirts in synthetic materials as skirts in general are rather breathable. Thick sytehtics with a good weave can last a long time and have the perk of being wrinkle free if you're getting the right stuff. I also like synthetic outwear as its not right next to my skin making me sweat but still keeping the heat in in a good way if that makes sense.

If you're on a budget like I am in my twenties, educating myself to hunt down quality has helped a ton. I've started to invest more in some pieces one by one by quality brands as things have worn out (shoes primarily) but until then, I will just hunt down those quality outlier pieces in person as much as possible and thrift what i can.

Honestly this. Coming from a female perfective fyi so I've covered a lot of surface area lol over the last three years. I bought one from the brand Zomchi on amazon in brass with embedded wood handle and it has held perfectly over the last 3 years (even with leaving it in the shower on accident half the time to let in steam in our unventilated bathroom lol) and looks the same as the day I bought it. All the pieces are easy to get apart so everything can be cleaned independently. Safety razors are innately simple in design as many have noted here so I don't think you have to get a something super expensive to get a long lasting item. Maybe just look into whatever metal is your preference.