I loop the end few inches and tie a double overhand loop. Snip the loop off and trim the tag end to form a spider knot. Form a 2 inch loop in the dacron and trim right back to the knot. lay the dacron loop at right angles to the elastic just below the spider knot. loop the dacron around the elastic and pass the dacron knot through its own loop and pull tight so the the dacron traps sthe elastic inside the dacron loop and uses the spider knot as a stop. Use a baiting needle and pull the dacron through the rig sleeve or bead and I finish it off with a dab of superglue where the dacron comes out of the rig sleeve or bead – but be careful on this bit – superglue can melt some of the beads that can be used and they can split.. TBH, not sure if its really needed.
Hope that makes sense – reading it back it looks horribly complicated, but works for me.