I cast a stick float in two ways. On big wide rivers like the Trent I cast out with a side swipe well past where I want the tackle to run down and feather the tackle down onto the water so that it lands in a perfectly straight line. Then wind the tackle back until it is in line with the swim.
With stick floats it pays not to fish too far out.
The other way on smaller rivers like the Idle, I wind in the tackle after the trot and bring it to hand. After checking the bait,rebaiting where necessary, I hold the tackle in my left hand, let go, and allow it to swing it out, checking the line carefully so that all lands on the water in a straight line.
On small rivers I like to use my centrepin reel, on big rivers, a fixed spool or closed face reel if it is windy.
Keep practicing; long trotting is one of the most enjoyable and productive methods of fishing ever invented. Your are hunting your fish too, whilst with legering, most times you are setting traps.
Oh and by the way, if you suspect a bite even though your bait is unmarked, change it.