Simple suggestions:
1. 6mm craft foam sheets (if you want that thickness) are available from: http://www.craftsuppliesforless.com/...amsheets2.html in a wide variety of colors.
2. O-rings can be placed on the collar of a fly for relocation adjustment http://www.oringwarehouse.com/ OR http://www.allorings.com/. Allorings has a good size chart. You use forceps to put one on a fly. Put the O ring on the forceps, open the jaws, put the fly between the jaws, close on the fly and roll the ring onto the fly.
3. Easy stiff tubing is available in the form of cocktail straws (there are two sizes and any bartender will give you a bunch). Besides, the search can be fun.
4. Gurgler patterns work great as strike indicators. I wouldn't suggest 6mm foam for this but a great option is taking two different colored sheets of sticky back 2mm foam sheets, sticking them back to back, and making two tone gurglers. Gurglers can be adorned with bucktail tails or wings, flash tails or Christmas wrap foam wings.