Rob's suggestion is something I did a good few years ago and it really works ...
What will happen is, simply, you'll spend what you have. I think you're already realising that you do spend too much, but can't see how you can manage by not spending it all. Using another bank account and keeping in there only what is reasonable for the month, and when it's gone, it's gone ... it'll find its own balance within a couple of months.
The rest? Save.
Save in an ISA for long term, perhaps invest for even longer term in the market if/when you have a decent lump to do that. Save in an easier access package for your holiday. Enjoy your holiday and proper blow out! Takes loads of spending money, splurge, be frivolous, treat yourselves. One good holiday, say in the summer and a couple of weekends away autumn and spring is how we do it and really look forward to it. Live within budget, or what budget you set otherwise.
Going out is not something we do much, what with me being a damn good cook and even proper fly restaurants being, well, a bit of a disappointment (personally, I like Chimichangas, a Mexican junk food joint), but we're getting into it once a month. The rest of the time, we eat very simply: meat, fish, shellfish, eggs and vegetables. Very little in packages, if anything, just simple veg and meat from the farmshop. I can come away with two or three carrier bags of food, full up for little over a tenner at the farmshop. Buy some things in bulk, too. Eat simply, eat frugally, cut down on the drink (no, do ... I know death is a long way away when you're in your mid-20s, but the seeds are sown now), so perhaps a bottle of wine with Sunday dinner, no drinking on school days, that sort of thing. We're not talking pennies saved here, nor pounds, but many tens, if not hundreds a month.
Cars are a huge overhead. Can you manage with one? Can you thrive with just one? Can you do without? Genuinely look into the mileage that you do and insure accordingly. Mrs saved over a hundred by dropping mileage from an assumed 6000 a year to a genuine 4000 on her insurance. Not much, granted, but perhaps folks at your end of their life may see a greater benefit.
Loads of ways ...
But, two which have made a huge impact for us are (a) live within a budget, set strictly in a bank account where when the money is gone, it's gone; and (b) eat more simply, eat out as a treat, treet drink as a treet not a way of life. Hundreds per month can be saved from simply being spent for no other reason than it's there.
Good luck!
