You should consider a number of things. If you make a conventional backcast with a weighted fly on the end of your line, a tangled mess often occurs. Standard flies on floating lines tend to slow near the end of the backcast, but weighted flies and lines do not they continue to speed rapidly away from the target. The abrupt change of direction between the backcast and the forward cast creates the mess. To solve that problem, make a backcast with a wide, open loop so there is no abrupt change in direction.