Buying your own cell phone! And then switching to Ting. We've been using the evo 4g lte which is a technological miracle, only costs $100 upfront, sould be able to sell it for half the price in about a year but got me off the terribly expensive 2 year contracts. What a scam those are, I'll never ever sign up for that again. We were paying $140/mo, now less than $60 without trying to reduce our usage.
Cooking with bbq also, I love it. Reducing eating out is a huge benefit, so cooking classes are good too. The resistance to cooking at home usually comes down to time and taste, both which are solved for me using BBQ. Also I think it's healthier, don't need to add butter and a lot of fat drops off, I usually do chk breast, veggies in olive oil.