I've not played many gigs this year, so I've not spent as much time practicing as I did last year.
Just lately I've jumped back on the gigging horse and that's forced me to pick up the guitar and run through some of my stuff.
Almost immediately I've started writing again, which is nice because I've been lazy.
This made me realise that new songs come from the same place my brain goes when I play the old ones. A quiet mind, focused only on the immediate act of playing music. I think it's like meditation, but I don't really know.
When I get to that place ideas appear out of nowhere without much effort. A new song starts as soon as an old one ends.
The hard part is to stay there for long enough to find all the pieces.