I manage the budget by prioritizing by critical and non-critical things.
Critical things are rent/mortgage, food, car and car insurance, utilities (water, gas, electric), at least one cell phone, and internet because I work from home.
Food shopping and mortgage are probably the biggest bills I have. I'm pretty frugal with food shopping, try to buy in bulk, and portion out meat by serving or meal before it goes in the freezer.
Instead of paying hundreds of dollars on a fancy cellphone & contract, I use a tracfone. Spent $20 on a dumb phone and maybe spend on average less than $15/month on service. I use an old iPhone for apps on wifi. Quit cable and get Netflix or Amazon Prime subscription.
Don't go out to eat. Cook from scratch. Stop buying coffee from DD.
Dive into thrift shops for "new" clothes or miscellaneous things around the house.
Going from "abundance living" to frugal living takes some adjustment. You'd be surprised how much you can save.
This is some good advice. I thought I'd just elaborate on your critical/non-critical idea. Cutting expenses is a great idea. There are a lot of ways to do it. The priority though should first be to establish how much much you have and how much you spend. Figure out how much your critical things cost first. Pay the things you absolute must as soon as you get your paycheck. This would be rent, insurance, utilities, monthly bills (internet, cell phone). They you'll see how much money you actually have left to spend. Pay off any consumer debt you have ASAP, starting with the the debts with the highest interest. Writing everything down will help more than anything. Then you can figure out have much you have to spend on food and whether or not anything will be left over.