Coping with a flight of ideas in employment

I've always had a problem where I come up with lots of idea and want to
do something about them. I've come to learn over time that these periods
come in cycles and I can't get all the ideas done. Some of them aren't
great ideas, others are but take a lot of work. What I used to do is put
them on a spreadsheet. Every time I had an idea that I thought was
worthwhile I'd pop it on there. I'd do nothing about it. I'd just let
the list accumulate. It was a way to take the ideas out of my mind and
stop me obsessing on them. It kept me focused on the work at hand. I'd
work on the better ones outside office hours if I felt they were worthwhile.

This is a fairly simple way for anyone to get out those 'mad' ideas and
focus on their job.