how do u use diminished stuff efectvely. obviously there is one diminished chord in diatonic theory, but is there a way u can use them more often?

or what cos i have heard lots of reference them but not really how to use them in a song.


also i made this little riff (sound quality is crap cos its my guitar directly into pc no amp between them.)

and i am pretty sure its diminished, but if u see all the notes i am usein a lot of chromatic notes. like at leat 9 notes are used. so i am thinkin i must be changin key or summti else is goin on.