Piano students sometimes take on too much when learning a new piece. They attempt to learn a whole section at a time or even worse the whole song! When this happens in my studio I whip out this picture that my daughter so graciously agreed to take as a visual to remind students that we eat a sandwich one bite at a time. Then we chew. Then we swallow.
Translated for piano – we learn one bite at a time – maybe a measure or right hand only or whatever. Then we chew. Play what we learned several times before moving on to the next bite. By now the picture is enough to remind my students to take it SLOWLY!