Rather than spending money on materialistic items, start spending your money on experiences. Buying materialistic things (clothes, cars, etc.) will give you happiness temporarily, but that happiness eventually fades. This phenomenon is called the hedonic adaption. Hedonic adaptation is when we quickly return to a relatively stable level of happiness despite major recent positive or negative events or life changes .
You rarely remember when you bought a piece of clothing, but you vividly remember your first concert or your first trip with your best friends. Experiences provide arousal and positive memories that last a lifetime. So instead of purchasing the newest shoes or the latest iPhone, spend your money on traveling, learning new skills, classes, and experiences that will help you grow as a person.
Time is the one thing you cannot get back.
Be smart with your time. When we're young, we take our time for granted until it's too late. Find ways to "buy" yourself extra time via services or apps. For instance, delivery services, paying someone to do tasks or ride-sharing services. If you feel you never have enough time during the day, re-evaluate how you can better manage your time.
"Lost time is never found again." – Benjamin Franklin
There's a plethora of research showing that the more you give to others, the happier you become. Make it a habit to give 10% of your money to charities that you believe in and support. Find ways to volunteer and give back to your local community and take the time to be there for others. You'd be surprised how much of a lasting impression this can bring.
"Whereas, on the other hand, there’s very good evidence that people who are generous, people who think of others, people who don’t just think of themselves are significantly happier in their lives."- Peter Singer
Donating a percentage of your money gives you an advantage psychologically as well. This is because the mind will believe that you are not tied to money and not a slave to it. When Tony Robbins had only $17 dollars to his name, he made it a point to give half of that to a family in need. After he gave half to the family, he said he never felt more alive and that changed the direction of his life. Live a life where you are serving others and giving back.