I just use mini handheld graters - like for nutmeg nuts. The rosemary from the garden I strip against the grain and use an herb chopper on my wood cutting board. The dried mint I just rub between my palms and the basil and parsley I shred/tear by hand.
But, I am told coffee grinders work well, although the one time I tried it, it seemed like it was more of a hassle and more clean up than doing it by hand. I used to have a pestle, but lost it in a move and although I really missed it at first, I'm fine without.