Feeding to sleep is the best trick in the world! My eldest did till she weaned (3yrs 3mo) and never had a problem transitioning to falling asleep without so I don't really believe the bad habit hype. My youngest is 18mo and currently asleep at the breast as I type, I like it because it forces me to sit/lay down and rest. And catch up on the world lol.

Do what works and enjoy, don't spend time worrying about books or rules or habits and mistakes. It all works itself out, listen to yourself and your baby and you'll find your own groove together.