Prepare a hooklength, tie on hook and double overhand loop the other end. Onto the mainline, thread a small ring (from a Drennan rig ring to a curtain ring), then a snap-link swivel and finally a bead, this bead must be a fine bore type (hole just big enough to allow line through).
With these threaded on, tie another overhand loop to the end of the mainline (leaving 12-15 ins of spare line on the tag end (Fig A).
Tie this tag end to the ring (using a four turn blood knot), encasing as you do so, the swivel and bead (Fig B),check now that the bead and swivel will not pass the knot and ride over the hooklength, then connect your hooklength,loop to loop.
The Matchmen’s rig, incorporating the double-loop (this gives a boom effect which helps stop the hooklength from tangling ) is shown in Fig C, this is in its simplest form, which will pick up very little "debris" in a moving water situation.
Endless variations are possible, swivel-beads can be used instead of link-swivels, beads can be used as "buffers" either side of swivel, but it is important that the weight is not "fixed".
You now have a self-hooking rig, that is safe to fish.