1) when i use a slip float i first tie on the float stop, bead, float, bead, then i tie on a snap swivel, snap first. that way i can add a slinky weight to the snap so that i can throw lighter jigs without re-tying to add more weight.

2) when drift fishing i also tie on a snap swivel snap first so that i can change weight just by snapping your slinky weights on or off.
(this also helps keep your line from twisting)
p.s. i use a no.2 ball bearing swivel