You just need some cotton fabric (a backing piece cut at 12 1/2" x 3 1/2" and several other pieces for front of mug), thin batting or fusible fleece (12 1/2" x 3 1/2"), a button, hair tie or stretch cording, the heart pattern available here:https://wombatquilts.com/2015/02/02/a-heartfelt-paper-piecing-monday/ and a sewing machine.
The tutorial follows here: