Give up meat, and learn to prepare and enjoy inexpensive delicious and wholesome food. Whole grains (including breads and pastas) and vegetables and fruits and tofu are inexpensive and good for you and you can eat very cheaply (and be much more healthy....if you doubt this, read The China Study)this way. If you are worried about getting enough protein eat tuna or salmon once or twice a week.
Get books, movies and music from the public library instead of buying or renting them.
Make your own coffee instead of buying that expensive stuff from that place on every corner.
Make your own lunch for work several days a week instead of always eating out.
Don't buy anything new if you can find it used in good condition. Shop at thrift stores, yard sales, and on craigslist. If you take the time to shop carefully you'll be surprised what you can find for practically nothing.
Learn to enjoy small and simple pleasures that cost little or nothing.
Instead of a gym membership, jog or walk or ride a bike.
If you have access to public transportation, park your car, or get rid of it altogether, and save a ton of money. Or even better, walk or bike to work.
Invite friends over for an inexpensive dinner and a video or music and conversation instead of going out to restaurants and clubs or movie theaters.
Don't deprive yourself of small things that make you feel good, because then budgeting becomes like dieting and you'll fall off the wagon easily. For example, I love good coffee with real half and half, so I get what I like, feel happy while I'm drinking it, and economize elsewhere on something that doesn't matter to me that much.
Hang out with people who are supportive of what you are doing and won't tempt or coerce or pressure you into spending money you need and want to save.
Buy locally, be a regular at the farmer's market.
Check newspapers for free or inexpensive concerts, art openings, and other entertainments.
If you have too much free time on your hands or are bored and frustrated by not having enough money, volunteer somewhere. It will keep you busy, doesn't cost anything, and you'll gather some good karma while you're saving up.