First, where do you live OP? I may have missed it but do you live at home or with your girl or in the dorm? Lot of good tips in here: there's so many ways to save and manage money that sometimes it's hard to list them all. I'll attempt to list some things I can think of that I do from the top of my head.
1. I know you mentioned sneakers and I also like sneakers. But I've learned from my first job and my experiences. Remember this: SNEAKERS WILL ALWAYS BE AROUND and THERE IS ALWAYS A SALE SOMEWHERE ON THAT SNEAKER YOU WANT. Half of the sneakers I currently have = I didn't pay over $110 on them (Jordans included). I'm always looking for deals whether it be coupons, sales on websites, a slightly used pair like 8/10 or 9/10, etc. My last pickup was some true blue 3s for $123 and the only thing wrong is the midsole chipping which can easily be fixed. When you find a shoe you like and wanna buy look around a couple of websites and stores before you make that purchase. If it's something like a retro release on a Saturday, don't be too upset if you don't get them because most of the time they come back around and sometimes come with deals you can use on them to get them cheaper.
2. Should've put this first but for this year, if you have all your receipts and statements, go back and calculate how much money you spent month to month. If you're lazy then just start tracking each dollar you spend for the whole month of May and determine where you need to cut back. I did that back in March and I realized I had spent over $1,000 - even though some of that money was for school and car, but still. Doing this helps a lot because you have an idea of what you're spending your money carelessly on.
3. For food, it gets expensive eating out. You really do not notice it until the end of the month sometimes or when that $20 you had in your pocket 2 days goes missing. If you can hit up Publix or somewhere and cop some fruit, chicken, etc and start making home meals. If you can't cook then cop some bread and meats to make your own sandwiches, get the BOGO snacks like the lays chips and separate small baggies for your self so you can have a little snack each day for lunch. You don't gotta stop eating out all together but limit yourself. They also got coupons for the fast food restaurants that come out all the time in the mailers that you can use which will save ALOT
4. If you can see if you can get that bill lowered. Maybe you can get a student discount, job discount, or do a family plan or something for it.
5. And always ask yourself 3 times "should I purchase this?" And when you ask yourself that question go into more depth with each response