Hair Ties (elastics without a metal band are best, fabric ponies lose their elasticity too quickly)
Assorted Ribbon (grosgrain, sheer, satins)
For this project all you have to do is loop ribbons onto the hair elastic randomly. All you need to know is how to loop. (You can knot, however looping is much neater.)
So easy it didn't even need words. Now just put a tiny dot of glue in the loop's "knot" to secure it. Ribbons like to come untied with this loop, especially grosgrain!
Now just fill it up! It can be as full or sparse as you like. Remember that it will be tied into the hair several times so it won't be too naked :)