Fun, easy ideas:
- Write short variations on the song;
- Embellish the melody with passing notes, mordents, trills, repeated notes, etc;
- Rewrite from simple to triple time;
- Compose an ostinato bass line;
- Change the rhythm, e.g. from steady quarter note movement to dotted rhythms;
- Inserting "echo" measures;
- Transpose into the minor (see below).