Yes, I also observe the precepts as a big help instead of just saying: "I would be better if I did..."
It is a matter of the unconcious mind - determination originates there. And there it can be destroyed again also. That's why I'm quite careful with engaging in talking too much about it. Sorry,
But once determined, it is no problem anymore for me how other people do. It is just a matter between me and me.
For examle, my band, they accept and love me as a non-drinker and a non-smoker - while they get high on some weeds and alcohol every rehearsal. It's their habit. But it doesn't touch me. I sit between them with my bottle of water or applejuice.
I know why. Because alcohol harms me, I'm determined not to take it.
But when the bass player describes the taste of this certain wine, i don't listen really. My mind doesn't follow. Otherwise it would be hard or impossible for me to hold the precept.
I think the precepts are a great help, because I don't want to do these bad deeds anyhow. If I had or had not the precepts, I have to abandon bad habits anyhow.