Are you using an Alvey, threadline or overhead reel?
If an Alvey, or even a decent threadline, you should try and use no sinker, if possible, or the smallest sinker you can get away with. With an Alvey, the swivel should be above the sinker to minimise line twist.Try the smallest ball sinker you can get away with running right to the hooks, trace, then swivel. This will cast without tumbling/tangles. If you want the sinker further up the line, try hooks, trace, swivel, trace with sinker, and a 2nd swivel.
I love Alveys off the rocks and often just fish a hook (or gang) and (if necessary) a ball sinker running right to the hook, with no swivel. Snags are minimal and if you do get snagged, re-rigging is quick and easy, with less rubbish left in the water. I can deal with the minimal line twist you get from minimal terminal tackle.
Cheers,
Baz