Here is how I do it:
Working on the back (or inside) of the piece, I push my crochet hook under the stitch just to the right of the tail.
Hook the tail and pull through to form a loop.
Work a slip stitch and pull the tail all the way through.
Tighten this stitch and your magic ring is secure. You can then use a tapestry need to hide the tail.
as well as on the front or outside!