This is my personal favorite lat exercise. I do a superset with pull ups and this at the beginning of every back workout, and now i could no longer put my hands in my pockets.
It's kinda hard to explain the right technique. I also had trouble feeling them in my lats at first but now i literally get a burning sensation in my lats. Maybe it's because i superset with pull ups, not sure.
I do them standing with an easy bar attachment, hips and elbow slightly bent. As you come down with the bar, poke your chest out a little bit and bring your hips forward just a little as you bring the bar to your pelvis.
What i would suggest is you do them one arm at a time and use the other hand to feel on your lats. Rather than coming straight down with your arms go outwards a little bit. This really works.
Use your index and middle finger to apply pressure to your lats as you come down on each movement. Just adjust you technique until you could actually feel your lats contracting on every movement.