I have only run 3 batches to date, all of which were simple sugar based. I then cut to 40% or 50% and bottled it for a week on a 1/2 cup or so of carbon. Next it needs filtered even though I originally boiled water and poured it over the dry carbon removing the most of the dust... yes 4 or 5 times.
What I have found is that a folded paper towel works good for a first or rough but quicker filter pass. I found the same with regular cotton balls, one stuffed into the funel and it works a little finer than paper towels, then there are coffee filters. Everything I've read references plain coffee filters at the base of the filtering tube, but I don't think that is fine enough and here is why.
I did some tests and thought what I had looked really good in a nice clean clear glass bottle. "Looks clearer than water" mmm hmmm we all know that look right?
That's after using paper towel, cotton ball, and coffee filters.
Years back I did some work (holography) uing lasers
so I have a few laying around. The simple test is take your laser pointer that you use for the pets (and your) entertainment, hold it on the opposite side of the bottle and point it back at you. The first time I did this I thought HOLY S^^^
and right away checked a glass of tap water after the bubbles settled out. Guess what was clearer? Yes the water indeed so to shorten this post up a little, I found that about 2 feet of rolled unscented toilet paper stuffed into the funnel and poking out just a tad gives me the best filtration so far, thus without researching and buying whatever micron filter pads or paper.... I can clean up my act and my drink, just not at the same time! 
Like I said, just curious what anyone else is using.
Cheers!