Mastering musical improvisation is a lifetime’s task, whether you are a classically trained musician who would like to be able to play in situations without sheet music or a new instrumentalist who wants to play without learning to read music. Beginning to improvise on your instrument could not be simpler, however.
Practice making noises with your instrument. Even if you are quite familiar with playing it, experiment with the range of different possible sounds, and how to make them.
Play a tune you know in a different pitch by starting on different note and playing the song in another key. This shifting is called aural transposition. Instrumentalists need to alter their fingering patterns to successfully play the song in a different key.