First, trace the outline of a wide-mouth, 20-ounce plastic bottle onto a piece of paper. Draw a vase shape around it that's at least 1 inch wider (or download our template ).
Cut out the template, pin it to two stacked pieces of felt, then cut around it. Seal the side edges of the vase with fabric glue, leaving the top and bottom open.
Decorate the vase by adding smaller felt shapes with glue. Lay it flat to dry, then slide the vase sleeve over the plastic bottle.