We did it by choice when we had our first child and I decided to be a stay at home mom. We lived on less than 20,000 a year for 2 years until my hubby got a better job.
Coupons for groceries, we ate whatever meat was on sale that week and I watched ads like crazy. Never enough money to stock up so just bought what we needed. We watched movies at home on tv no going out. We didn't eat out. We seemed to have more friends and more time when broke and took advantage of it. At the time our rent was $900 a month so not sure how we managed but we did.
I would figure out the bills and arrange them by due dates and juggle them, not everything got paid every month but nothing ever got disconnected. At the time the late fee was worth it to hold off paying it on time.