Many of your friends are on equal employment levels now, but it won't be long before some rise and be in positions to level you up.
I met a lot of retired people while I traveled who all wish that had done it in their 20s. It's possible to do it cheap and will be some of your best memories.
If you can't buy it with cash, don't buy it. Pay off your debts as aggressively as you can. Being frugal isn't that hard. Do a monthly budget and review your expenses. I found out I was spending $8k a year on restaurants and beer. Had no idea it was that high.
Most people I know in their 30's say they wish they were honest with themselves about who they wanted to be. Being honest about yourself makes setting goals and achieving them much more realistic and satisfying.
Exercise regularly. Eat healthier. My metabolism pretty much decided to stop working. Way harder to stay in shape now.
This was a lesson I wish I internalized earlier, as it has made me much happier. I can't control other peoples actions, so I don't expect people will do what I want. Makes processing the world easier.
Art, science, business, psychology. Whatever floats your boat. It makes life full and opens up new and unexpected doors. There are so many amazing (and free) resources out there.
You only get one life, so you might as well not lie to yourself. It's usually one person in the pair, but their inaction draws out the pain for everyone involved.
You cannot make a girl like you, you can however find a girl who likes you. Figure out how to be confident and have fun with whoever you're with. If it's important to you.
This is more personal. I always used to make excuses, and talk down compliments. It's just a lame thing to do. Now I just genuinely say thank you. It's surprisingly easy.
It's easy to get caught up on moving through life. I found someone who was great at truly being present, and learned from them what that meant. Even when doing the dishes, I try to think about the water hitting my hands, or the sounds of my neighbors outside.
Music is on the front line of culture and is always fluid and changing. Look for new music. Even if that's just cruising through YouTube or Spotify and you find an older band that you've heard yourself, that's new music. I feel like once you settle on music you'll settle on pretty much everything else in life. Keep looking. Keep exploring. I know people in their mid-20s that already have mentally checked out and have the life they're gonna live until they die. Don't be that. Keep looking for new stuff.
If you think about what happiness is, it's appreciating what you have. When you think of something that would make you happy, you are imagining yourself appreciating it when you get it.
To be wealthy, don't try and do tomorrow's work today, just have a successful day each day. If you have more successful days than unsuccessful days, your wealth will grow. As you have successful and productive days, opportunities will be attracted to you.
Mediation gives you the ability to be your best. Very handy for improving at anything, particularly gaming, as you see more and learn more. It gives you access to creativity in solving problems and improving your performance
Arrange a bi-weekly game night or movie night or anything. Otherwise two years will go by since you last saw that guy and hey why haven't you gotten together sooner? You used to be besties.
Just enjoy your life, do what makes you happy and don't worry about turning 30. I'm 34 and I haven't got a clue what I am doing or where I'm going, I just know that I'm going to enjoy it because I ain't looking back in 30 years and thinking I should have done this or I should have done that.
Foster it, practice it. It's a hell of a thing to see older people who do nothing but sit in front of the television because that is all they can do outside of their jobs.
Establish yourself, have some fun and get it out of your system. 20 year old me had my share of fun, 30 year old me is focused on my wife and kids now. 50 year old me is planning on being that weird eccentric guy that wears Hawaiian shirts and socks with sandals because my kids are grown and my wife has already invested so much of her life in being with me that she just has to accept my quirks.
Enjoy life. No one can enjoy it for you.
Some of the answers have been edited for clarity.