What a great topic and an opportunity to pontificate, which you know 54-year-old-me can't pass up.
My financial advice:
1. live below your means. Don't wait to save because it will never come. I've known people who make $200,000 who are financial idiots and people who make $50,000 who live decently.
2. Hide money from yourself. Yank the money out of your account before you ever see it so living on less becomes a habit. If you have a 401k, and a company match, it's free money and you should be taking advantage of that. (More important for the CF--no tax deductions.) My 401k goes into index funds, not a particular company stock and they match 5%. Because my 401k is not tied to a particular stock, I max out and have been since 1993. If you do the math, I'm in pretty good shape for retirement. Oh, and it goes without saying that you should never borrow from it unless you are seriously ill or it's a true emergency. I have known idiots who make $100,000 a year, and they live in places where good housing costs $150,000-200,000 and the cost of living is low, yet they raid their 401(k) regularly. The same goes with home equity. I know a moron who suddenly saw all this "equity" in the housing boom. (Translation: values were over-inflated) So she took out a home equity loan for a tummy tuck and boob job. You want to own your house free and clear some day. Home equity is not free money.
I live in a moderately expensive area, and I managed to afford 20% down on my first house. It took a long time and diligent saving, but i did it.
I send money into an investment/emergency fund, been doing it for ages and I have a vacation fund and another saving account too. I make sure the money goes to into accounts that aren't particularly easy to access. (No debit card.) If you have a car payment, after you are finished paying off the car, put the payment automatically into savings so when you have to replace the car, you'll have a bigger down payment or can pay cash.
3. Separate your paycheck from your checking account. It's human nature to see what's in the checking account and feel rich and your wants start cropping up. I deposit what's left of my paycheck after deductions into a savings account that's tied to my checking account. I transfer twice a month. That way, I get a quick and dirty idea of what I'm spending.
4. You can dribble through a lot of money and not get satisfaction for it. Figure out what really gives you pleasure and cut to the bone what doesn't give you value.
All the self-denial in my 20's-30s and 40's has paid off now. I can indulge my wants, but I'm still careful. I never had a pedicure until I was over 50. I like them now and I wait until the place I like has special and I use a groupon. I color my own hair and get professional highlights so it only looks expensive.
I go to a medi-spa where I get laser treatments for my face and body. I buy them on Black Friday when they are 75% off. I buy clothes on sale whenever possible. Stay out of the fake nail thing--it's bloody expensive and terrible for your nails. Same with eyelashes.
Oh, and to add what Hannigan said about aging....women typically age a lot between 40 and 50 and beyond. Do not fritter away tons of money on nail, hair and face crap when you are in your 20's and 30's. In your 20's and 30's you look good because you are young. Put some money in sunscreen or you will kick yourself later, but save your beauty money for when you really need intervention, when you are 40+ or 50+, particularly if you want to stay employed. Age discrimination in the job market is a very real thing after age 40. It's sad our culture values youth, but it does. That's another reason to save your money when you are young and your earnings are higher---the only job you can get after age 40 may require belt-tightening.
Some of this is frivolous, but the best reason to save money is freedom. Because I had saved my money and had no kids, I was able to leave a job I hated and go into a field I liked better, even though it meant making less money. I worked with people who had kids and obligations and they spent every dollar they made, so they had no other option than to stay in a miserable job. Earnings wise, I eventually caught back up. It took about 8 years, but it was worth it. Life is too short to do what you hate. Sometimes you have to suck it up, but if you save your money and live below your means, you won't have to do it forever.
Other advice:
Take care of your body. Garbage in, garbage out.
Stop giving a shit what people think. People who are pressuring you to sprog just want you to be stuck like they are. Life is about the long haul--I've known people who told me having kids was the greatest thing evar, and they got all kinds of social validation, yet 10-15 years later they were divorced, broke and/or miserable. Think for yourself and know yourself.
Do not believe that old age is automatically suck-y. I recently read a quote from Jane Fonda. She said aging only looks scary from the outside. This is a great time of life for me and it's no accident. Not having brats just keeps paying dividends. I look at my friends who are haggard and broke, and 90% of these problems are due to children and grandchildren.
Never underestimate the impact your family had on you. It it was bad, get some therapy but don't stay with a therapist who lets you linger in self-pity. Read a lot of books if you were raised by idiots. My parents looked prosperous, but my mom is an emotional idiot. Be willing to entertain the notion that not everybody lives like that and there are other ways to live your life. (12 step programs are helpful if there was alcohol or substance abuse.) Confront your parents and de-mystify them. They are just people and people make mistakes. It wasn't about you.
It's taken me a lot of work, but I live in a peaceful house now. I'm much happier than my mom ever was. I'm also learning and growing and there is room for fun and healthy hobbies in my life. Fun is under-rated.
Relationships:
It takes at least 2-3 years to get to know someone. I've had two failed marriages. I dated #1 (brief starter marriage) for a ridiculously short period of time (6 months---MADNESS) and #2 for a year and it wasn't long enough. I've been with #3 for 15+ years. He's that spectacular, NMNK, CF, or I never would have considered getting married again. I dated him for four years. Surprises are only good in the movies.
Make sure the person you are with is disciplined and can delay gratification, in other words, is a grownup. There are a lot of people who are running around in grown-up bodies but they are emotional children. Look at their life and see how they conduct themselves. Do they pay their bills? How do they relate to you when they are tired or stressed? When you have a disagreement, are you able to talk it out like reasonable people? And under no circumstances should you stay with someone who lies or has anger issues or substance abuse issues. Eventually they will lie to you, humiliate or hit you or sacrifice the relationship for the addiction. It's never worth it.