Of late I come up with chord progression ideas sitting on the lounge strumming my semi acoustic while my wife is trying to watch telly. If she's not around then whilst doing the same as above but watching the cricket is a good option.
Seasonal writing then? No, non cricket season here is cricket season in the UK or S. Africa or the Carribean. & yes it often starts out with.."Yes, I don't like cricket... I love it.(dreadlock holiday)".
Lyrically? I have a wad of stuff from my drinking days that are a great starting point - failed poetry as a starting point for songs - well, it can be art if you can tart it up with a musical backdrop.
There was also a period when my trade union activities stimulated a lot of lyric ideas but I had to turn that tap off as Billy Bragg does it SO much better.
These days I just play with words and enjoy collaborative writing or, even better as the pressure is off, editing the writing of others.
My handwriting is so poor these days that writing has gone through typing to straight up word processing which can be handing for editing.
My biggest problem is, as said by someone else somewhere - I can't sing a note so creating a melody is much tougher. I usually wait for a vocalist to do that for me.