For me it was a process of knowing it was bad for me, and gradually ramping up the amount. I read up on the damage over drinking did, and scared myself with some of the stories. So I spoke to my doc, and he said I should aim for not drinking at all. Big scary words! However not long after my DIL took up smoking again and I was thinking she should have stuck it out. Suddenly realised I was just as bad with drinking, and that was the final incentive. It was 'easy' after that because I'd luckily had that final motivation that makes all the difference between knowing and doing.