When I placed my initial order, I bought a box of the make-your-own tea bags (see tea accessories page). For about $3.00 you get 100 filters (I've yet to use my whole box in 2 years...) and they work wonderfully.
I use them when making a cup of the rooibos teas, or any of the fine herbals (like spearmint, peppermint, lemongrass and cha cha). I highly recommend them as they are a simple and affordable solution and the clean-up is far easier than trying to pick out pieces of tea from the slits on the glass infuser.
Try them. You won't be disappointed.