hey, about hi hat loops , the most easy way(if u use fl studio) is fill the drum bar with
1010101010101010 for example this is the music bar
1 is a hit hat
0 empty
this is the most useabel hi hat programing in the hip hop music .
but from my experience there no rules for hi hat in the hip hop or urban , u can put it where u listen it good ,
note ( im not very expert in english )