Are you looking for Contest Solos? Try THIS PAGE for suggestions on various levels of solo with piano accompaniment.
One of the things we can do to make ourselves sound more musical is to shape our phrases, both dynamically and with tempo. At the end of many songs, we can place a rallentando (or ritard) and give the song a feeling of relaxing or coming to rest. The following PDFs have several melodies with which you can try to accomplish this. Also, listen to my performance of the melodies to get the idea of overall dynamic shape and tempo.