You know the problem with rulebooks? There's just so many darn rules! I know how it is - some rules are just too complicated or time consuming to enforce. Maybe you were a new GM and you jettisoned those minor rules that just slowed things down. Maybe you were running a game for some new players and you didn't want to scare them away with these extraneous rules. And then you sort of let them slip away, because the game worked just perfectly without them.
Well... I think it's time to re-evaluate some of those rules. I've played a fair amount of D&D in my time, and I've read of and heard a lot of other peoples' stories as well. From the experiences of myself and others, I've identified a few rules that often get ignored (not all the time - very possibly not even in your games - but often). Now, I totally understand why these rules don't always get used: I've neglected many of them myself. But they were written for a reason, and I think they might benefit from a little extra love.