The words "I can't afford it" are part of my vocabulary.
This would solve 99% of people's problems with money.
This is the most important piece of advice. Sure, you don't know other people's full financial situation, they may have family money that they are using to go shopping every weekend and buy brand clothes.
Or they may have credit card debt. It doesn't matter too much.
What matters is that you must know your own financial situation AND your goals. If you cannot afford to go to the same expensive sushi restaurant then don't go. If you cannot go to the movies every weekend, don't do it. Etc..
It is not just about what you can physically afford in the moment. Rather, can you afford it long term? Does it fit with your long term plans?
Don't buy the cheapest shit possible. You'll spend more in the long run.
Also don't buy the most expensive, it usually does not make sense. If you don't think whether you will be using the thing a lot, buy a cheap (not the cheapest, but on the low side) version. If it breaks from using it a lot, buy a good one.
Hobbies are not a "right". If you cannot afford one hobby, well, too bad. Find hobbies you enjoy that you can afford. If you find a way to do an otherwise expensive hobby in a way that's sustainable for your finances, then it means you can afford that hobby.
If you cannot buy outright your phone, you cannot afford it. Buy something cheaper, it's okay.
Research taxation on investments, pension, etc.. in your country. Actively managing your money can result in a lot of money saved/earned - or just not lost because you didn't bother understanding how to properly store cryptocurrency.