All chrome 6" Wonder. 20 feet behind the clip.
Or sometimes add a green daisy chain just above the ball. Clip 3 feet above that.
Make sure your stop is set to kick before you knock your clip off.
I've knocked off a few clips because of this error...so my trick is to add a short line as a safety for the clip, attached loosely to the rigger line.
Get an 8 foot cord end for the downrigger. So the cord acts as a natural stopper at 8 feet, then a 1 foot snubber, then the cannonball.
No need for the yellow or orange rigger stoppers, because the cord takes over that job and WILL NOT MOVE.
Attach the clip to the cord as usual, just low enough to avoid getting bumped off. Add a short (8 inch) piece of line to the clip harness, and clip it onto the downrigger cord as a safety. This way when it inevitably pops off, you don't lose your clip harness.
Attach the dummy to the snubber. Long enough to avoid getting it wrapped around the downrigger line. Roughly 4' plus.
Use a triangle dummy flasher, which is way less likely to wrap itself around the rigger cord.
The result will be a line clip about 6' above the dummy.
With this setup I still get tangles once in a while, but not bad.
I let the spoon follow the dummy flasher by at least 6 feet. The salmon seem to find it just fine, pretty much any distance behind the dummy flasher.
I should take a picture...but i'd guess anyone using scotty riggers probably has long figured out that the stoppers are imperfect and an 8 foot cord end is way more reliable.