Here is a step by step for a gurgler I did years ago.
Step 1. Tie onto the hook. Wrap the thread down towards the bend of the hook. Then tie in the tail of the fly it can be quite long. Add some flash to the tail as well.
Step 2. Then tie in the foam with this would need to be about twice the with of the eye of the hook maybe a bit smaller.
Step 3. Tie in the flashy stuff I used crystal chenille for mine and wrap this up the shank of the hook. Not right up tight to the eye.
Step 4&5. Fold the foam back over the chenille towards the eye and give it a few turns of thread, The tag that is sticking out over the eye needs to be folded back over the hook to create a loop tie this down and tie off the thread. Cut the loop that has been formed to make two seperate pieces of the foam.
Sorry about the fuzzy pics difficult to focus with the crappy camera.