1/2 oz is a good size, one of the most popular colors is chrome/ blue back.
I haven't bought a Bill Lewis Rattle trap in a long time, but when I did the hooks were crap, not sure if they changed them, but if not make sure you do.
From the sounds of it, it is a normal trap pattern, let it sink down until you hit the grass, then rip it free then try and keep a steady pace right above it, letting it get caught up a little, something about the ripping it out part that triggers the strike, can also do a yo-yo type retrieve, ripping, letting it futter and ripping.
I should take my own advice and try this today as that pattern should be getting ready to happen here pretty soon.