I find occasionally wandering off the major/minor scales into a more modal territory often helps create more interesting melodies :)

There are lots of tutorials, videos, pages etc. out there explaining what the modes are all about, totally worth a shot trying them out!
(Knowledge is power, right? )A personal favorite of mine is trying to mix different minor scales with phrygian mode, or the other way around, as it brings a lot more harmonic possibilities.