If you want to train with light weights, keep your negative eccentric of the reps quite slow under control & let your muscles stretch at its full length in every rep, also push or pull your positive or concentric phase explosively & squeeze hard at the peak position of every rep. If you train heavy, you can do your reps with slightly greater momentum in both phases but still keep your posture tight & go for full range of motion to achieve maximum stretch & contraction in your muscles. Brand amba