The beauty of inspiration for me is that you can't predict when it's coming. I like that it just pops up out of nowhere. You just have to be open to its arrival.
Songwriting never feels like it's me doing anything consciously except for becoming aware somehow that it's time to let something out, or let something in, depending on how you look at it.
I tend to play covers when I'm gearing up for creating new song. Singing other people's songs is a way that I get inspired.
I give myself time with a guitar and PA to let my subconscious do its thing. This happens repeatedly over a period of time, and slowly, a set of songs emerge that make some sort of sense to me as a body of work that turns into an album.
I've never thought to notate my songs...I tend to just have to remember them.