The same method can be used for itty bitty tassels (like I use on my shirts), or big huge chunky tassels, like in my Tribal belts.
Same method, different outcomes!
Itty bitty tassel is out of thread and fine cord.....big chunky tassel is made out of yarn and braided chunky cord.
2. wrap the strands that will become the tassel around a card or CD case or whatever - just make sure that it is 2x (plus a smidge more) wider than you'd want your finished tassel to be.
Wrap 'round and round until you get enough 'body'. This is totally subject to personal preference, but you don't want your tassel to look skimpy. Neither to you want it to be so boofy it's unmanageable. (Pro-tip: don't wrap so tightly you can't easily slide the card/case/whatever out after you're done wrapping!)
3. Take a long piece of strong thread/string/yarn, and tie a knot in the middle of the wrapped threads.
(Pro-tip: You'll be using this same thread to tie off underneath the 'balloon' portion of the tassel, so you'll need to decide if you want this string to match or contrast the body of the tassel.)
4. I find I get plenty of stability just by butting the two knots together and skipping to step #5. If you are worried about your tassel falling apart, tie the cord around the knot you just made. This makes the body of the tassel bigger, and sometimes it can be harder to hide the ends of the cord, so experiment and see what works best for you.
5. Now, this is where keeping your knotting thread long comes in handy!
Arrange the fringe around the cord, so there are no huge gaps (don't worry if it's not perfect, you can fiddle with it at the next step. Just make sure it's not all clumped together)
Now, take those long ends and wrap around the fringe and the cord, just underneath the knots. PULL TIGHT!!! Do a bunch of square knots to make sure everything is secure. (I guess at this point, if you were really worried, you could do a dab of glue on your knots, but I've found it to be unnecessary.)
6. Now, flip all the fringe the opposite way. Arrange all the fringe to be nice and smooth over the body/bulb of the tassel (This is where you want to be extra-picky. It's going to show, and it's hard to fix after tying off!)
TIGHTLY wrap the long tails underneath the knots. Knot off the ends. (I usually to back into the middle of the tassel and hide the knots in there).......and voilà! You've just made your very own custom tassel!
ETA: 7. Trim off all the loops to make the bottom of the tassel even! Heh.