More precisely: Don't use credit cards to carry a balance.
By not using credit cards, you're giving away 1–5% free reward money from cash back programs. Not to mention the additional purchase protection you receive from shoddy vendors, like bars padding tips.
Best way to not carry a balance is to not have a credit card. It's very easy to say "don't carry a balance" but most people do. When I used credit cards I often carried a balance, despite my best efforts. If you have the discipline to NEVER carry a balance, more power to you. But most people don't and the points just aren't worth it.
I've never felt like it's taken much discipline for me personally, and I've never carried a balance on any credit card. I try to live far under my means and mostly just spend money on food, coffee, travel, and a laptop. Most of the rest of my "things" are hand-me-downs.
One "hack" that works for me is reviewing each transaction and paying the card in full every week. If I see it especially high one week then I spend more conservatively the next. I don't do any explicit budgeting, but being conscious of the big picture helps me.
Definitely use credit cards. If you know how to manage your finances (i.e. spend about 40-50% of what you make and save the rest), it shaves off 1~2% off of all your purchases.
This is even before mileage, hotel stay, etc. rewards come in.
By not using credit cards, you're giving away 1–5% free reward money from cash back programs. Not to mention the additional purchase protection you receive from shoddy vendors, like bars padding tips.