you may or may not remember a thread similar to this, but, whatever. I can kindly make up solos, but should they be more high pitched or low pitched?? In case you were wondering, I play stuff like Megadeth, Metallica, Black Sabbath type music.

Go from high to low, but high solos will come through in songs better generally.
Do whatever sounds good in that particular part of the song. Variation is always good so feel free to spice things up a bit, you don't want all of your solos to sound the same.(*cough*Dragonforce*cough*)

You shouldn't really have a set plan for doing solos, for example writing a song and just deciding it will have a high and fast solo in it without trying anything else.