According to some of my girlfriends it´s easy enough.
You just have to create an instagram profile, post a bunch of pics of yourself doing cool stuff with the right hashtags, post at the right time to get more visibility, colab with other people to reach a broader audience and of course put that you are an influencer in your bio.
I believe with the exception of one all of them still live with their parents so I can only imagine how much money they are earning/saving monthly!
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I´m not rich by any means but I live a good life for people around my age.
My tips would be start saving and investing as soon as you can, you put money on a portfolio adjusted to the level of risk you are comfortable with and just let time do it´s thing, it´s like having a little you working in the shadows creating value to your account.
Don´t go out too much to party, it´s easy to spend 200€ in a weekend just by going out at night and have some drinks in the hottest place at the time, even here, most of them are tourist traps anyway. You still can do that and spend a third or even less if you avoid those places. In the end of the year that means a lot of money.
Also for me is not spending money on things that I consider a waste of money, but that´s subjective obviously I like to travel and many people consider that a waste of money.
The example I always give is cars, it´s nice to have a flashy car but as soon as you leave the shop you already lost like 20% of the value and you´ll just have to continue putting money into it, a nice car means expensive repairs, insurance, tax related expenses, gas.
My car is currently 12 years old but it´s as good as new and is good enough for me, most of my friends are on their 2nd cars and looking for the 3rd because kids and stuff. BMW and Mercedes are a must in Portugal, everyone loves them but they are above a lot of people budget, specially younger people, but with the right credit in 5 years you can own one so it´s awesome, as awesome as the interest they charge every month.
I understand that makes me sound like a bit of a twat that thinks he´s better than the rest of the people but that´s honestly the mistakes I keep seeing people do the most.