For the photography the white cord represents your rig line and the green elastic band has just been cut. The two pence coin is for scale only.

To create a stop knot from a elastic band sold in most supermarkets and as above in different colors that can be used  above a float to determine the depth from float to bait.

Using  a elastic band is ok to be used on the fishing rig but not on line that will go through the rod eyes.

Lay the elastic band along side the rig line and then wrap the elastic three or four times around the rig line holding them together when you wind the elastic around.

Bring the tag end of the elastic band around and make a loop and then pass the elastic around the line  inside the loop three or four times.

Pull both tag ends slowly and wet the knot and then pull tag ends again.

Move the knot into final position and then fully tighten by pulling both tag ends.

This is the knot complete and as you can see i have wound the elastic around three times and formed a loop and again around three times inside the loop and pulled tight.

If you are using this as a stop knot for a float leave the tag ends on.

If you are using this knot as an alternative to a crimp on your home made rigs trim the tag ends off leaving a neat knot.

If you feel that one elastic knot does not provide enough support for your hook snood put two elastic knots onto your rig below the swivel and bead.

With the elastic coming in different colors you could color code your  rigs or hook size 1/0 red 2/0 green 3/0 yellow and so on.

The two photos above show the knot below a size 1/0 hook snood using a Yellow and a Red elastic band.