Stand on a bench and jump off. Look where your feet are after you land. That is where you want your feet to be for a conventional deadlift. That is the best way I have found when helping others with deadlifts to get the right foot position. Typically it is shoulder width with toes pointed slightly out. My stance is a little narrower than shoulder width but not by much. As for the grip, I use a reverse grip (one overhand and one underhand). When you start going heavy, I think you need to use the reverse grip to keep the bar from rolling out of your hands. And for heavy lifts, you should grip the bar just outside your legs. My arms are actually rubbing my legs on heavy sets. If you grip too wide you are just increasing the range of motion for the lift. Some people may disagree with some or all of what I said but that is how I do it ..and I am a deadlift-aholic.