Tony,
When I fish this method I use Peacock Quills, but a small waggler is OK.
First the float should only be attached at the bottom only with a float rubber, make sure this is nice and tight, or the float will slip up the line.
Plumb the depth of your swim as normal, so the float is just showing the tip by an inch, you then move the float up the linetwice thelength of the float, IE if the float is 4 inches move it8 inches.
I thenput one BB shot the same distance as the length of the float (ie 4 inches)from the hook.
When you cast out, the float should first lay flat on the top of the water, just tighten up on the reel a little, the float will start to cock, do this until the float tip is showing just an inch. It may take a few goes to get this right, if so just move the float back down towards the hook an inch, until you are happy setting the float.
When you get a bite, the float will lift and lay flat, just strike, but the float may also just go under, with this method you don't always get a lift bite.
Hope this helps you out, others may do it a different way, but this is the way i find works for me.
good luck.