Fold the coffee filter vertically, around one inch away from the edge on both sides. Cut away the side pieces, leaving the middle strip.
Pour a scoop of tea down the middle of the middle piece. Fold in half, then fold the edges over together twice. Move the seam to the middle. Fold in half.
Fold the top corners down to a 'triangle shape'. Fold the pointed middle down, then sew a few stitches in with needle and thread. Tie string to cup handle, or attach string to a tag.