Put your heels close together and point your toes out slightly to really target your quads.
I like doing these with lighter weight at the end of a lower body workout, and I actually feel them more in my quads when I drop the weight slightly and focus on keeping the form tight and the reps a bit slower than when I just go as heavy as possible. As such, I keep the reps higher as well, usually in the 8-12 range.
I don't recommend doing super slow eccentrics (negatives) on the deadlift, but you definitely want to control the weight here and not just let it free fall as you might when pulling maximal weights. If you're the type that needs a specific cadence, shoot for two seconds on the lowering phase, but don't be too anal about it.