The more familiar you are with a scale, the easier you will find it to play melodies created from that scale, and the easier you will be able to create your own melodies from the scale. One of the best ways to practice scales is the use of sequences.
A sequence is a repetitive pattern in which the rhythm remains the same while the pitches are repeated higher or lower, usually within a specific scale. Practicing sequences is also good for your co-ordination. Remember to use strict alternation with right hand fingers on all the eighth notes. Here are some sequences within the C major scale.