When it comes to the Sumo Deadlift stance, you want to find a stance that is not only comfortable and with, but also effective. The Sumo will always have your hands inside your knees as compared to the conventional where your hands will be outside of your knees with a much narrower stance. When it comes to the conventional stance, you want to line up about hip width or a little bit wider depending on comfort level, but you want to make sure that the bars directly over the midsole of your foot. As you start each rep, you want to engage slowly and controlled off the ground and explode your hips through towards the bar at the top, squeezing your glutes up. Another thing you want to engage is also your lats to help maintain an upright, flat position with your chest out. This is going to also be done by taking your elbows and squeezing them down towards your sides as you start each rep. Make sure you drive through your heels on each rep as well to help engage those glutes, hamstrings as well as your low back. And not allowing that low back to do the majority of the work.