I setup two lines - one about 20 inches the other about 16 inches. Both had a swivel and hook.
I then thread the 16 inches prepared leader to the main line. Next tied the 20 inch swiveled leader to the mainline.
My issue may have been the swivels quite cheap, as inherited from my father in law. I need to buy some decent ones, but a bit short on cash at the mo.
hmm, try shorter leaders if that is the case. I have cheap ones too so I ended up doing 8 and 12 inches. if they tangle, because they are shorter, they untangle easier!