first when going down pluck/sweep down UNTILL you get to the last string pluck?sweep up. this makes it easyer to play the next note going up and helps you not to stuff up by playing the same note again.
secondly dont start off on somethin hard and fast start off slow and easy.
like starting off with 3 strings to start off the sweeping motion.
and when you get better add ome hamerons and pulloffs it will make it sound allot better and get your hand quardination great.