I've seen these fuzzy nails all over the internet recently and to do them you need something called flocking powder. I have no idea what their actual use is or how much they are but I do know you can get them at craft stores. Apparently they come in a bunch of colors. My advice: don't bother. Save your money and just use cotton balls. I'd be willing to bet as nail art enthusiasts that you already have some laying around. I used barely even half of one for a whole hand today (I can't show you the pic just yet since it's going to be part of this year's 25 days of xmas nails). It was slightly more messy as you get some polish on your fingers but no big deal.
All you do is pick the color you want your mani to be, do the one coat, then when it's dry do a second coat on one nail at a time and while it's still wet, place little bits of ripped up cotton ball on your nail. Pressing down causes the cotton ball to attach to your nail and change to the color of the polish. I still had little bits that were white so I just took the brush and dabbed color on that spot and then pressed it down so it's more attached to the nail. This way you get the look of this fuzzy nail trend but way cheaper since you don't have to buy anything extra. Win! Also it was super easy to take off since the color is already on the cotton ball parts. Double win!