A meandering mind has helped me. I often have tunes running through my head. Sometimes they're tunes I know and sometimes they're ones I created. I have no clue how some of them get there, but I tried an experiment once. Stuck a well known jig in my head on my way to buy groceries and deliberately changed a couple notes, then let it wander where it wanted. I came up with this. You may hear the familiar tune in only the A part because I think I pulled it out of my head when I got home and wrote the rest on computer.

It's hard to do this intentionally. I mean, I can stick a tune in my head and just leave it alone and see what happens. Often, when I try to change it on purpose - when I think about it, I don't have as much success. For using 'hooks' from other tunes, try putting them somewhere unexpected in the tune, like at or near the end instead of in the beginning.

Mr Red, funny you should say that about the left-handed guitar. I'm just trying a new tuning. I was consciously working out chords, then just started messing around. Wound up finding some chords that sounded weird but good, and picked strings in those chords. I wound up with a little tune.

Although I can write a tune methodically, my easiest and most fun experiences come out of the 'happy accident'. I quit paying attention, make a mistake, or just try something new, and wind up with a new tune.