5bb insert clear crystal waggler for 3-4 rod length casts, 7bb if further-both are for calmish conditions.
If wind and ripple to combat then a thicker bristled float up to 3AAA. If there is tow in that, just go with the heavier float option so you can tighten up to it, cast beyond your target area, sink the rod tip and twitch it back to sink the line, you can also lay a little bit more line on the deck by going overdepth in order to combat tow.
Always fish it dead depth usually and a good tip when plumbing at distance and to achieve dead depth accurately, is to leave the bail arm off and line slack as you are waiting for the float to appear up. Plumb up with just a couple of shot locking the float, once at the right depth, add the droppers, then more to the main bulk until right. Might seem odd, but if you get the shot around the float all done first, it can then be an issue getting the right number of droppers in, for that reason I go droppers first straight after plumbing.
A quick change float adaptor is essential if you need to alter things during the day. Hook wise is a drennan maggot red to nylon, start on 20 to 2'12, up it to an 18 on 2'12 or 18 on 3'6 if larger fish and/or carp appear. Mainline is 4lb.
Have 75% of the shotting around the float, but build into that some no'6 shot should you need to get a bait down quicker and slide one or two down to the 3/4 depth mark. In a five foot swim a couple of no'8 shot spaced equally apart from the hooklength join is usually sufficient to give a decent fall to the bait and encourage bites almost immediately on settling if the fish are in a follow it down mood. If deeper, then add a 3rd number 8, again equal distance up from the next dropper. Your main shot loading should take the float down to the base of the bristle, then the droppers creep it down to the desired amount of show-as little as you can see I would say.
Feeding wise (maggot), although a little and often (feed then cast over it) works generally, sometimes a bit more feed and fish it out works. If bites are hard to come by, or you were getting regular bites at a set time, but now the float goes out and just sits with no bite, feeding a small amount over the top always seems to encourage a bite.
Points about length of rod are spot on, a 10ft rod is fine for shortish casts, going up to 12ft or 13ft for longer, picking up the line on the strike must be factored into this decision too, a longer (with a soft action as mentioned already in the thread) will do this well and if it comes to a choice, then longer is best. You will quickly see if you have got this one right, if you continually don't connect with bites, the larger hook option sometimes plays a part in that too.