Another important scale commonly used in Hard Rock and Metal soloing is the harmonic minor. Its formula is shown below, along with the fingering for the E form of C harmonic minor. The only difference between this and the natural minor is that the seventh degree is raised by a semitone.
Once you know the basic fingering, try this lick which is derived from the harmonic minor scale.
As with all scales, it is important to play licks from the harmonic minor up and down the fretboard in all keys. Here is an example in B minor to learn and transpose.