This is something I am constantly trying to get better at.

I have recently started using jrnl: http://jrnl.sh

I really like it because you can export it any many formats which I think would come in handy later to import the data, say a database. I always like the idea of a flat file for right now so you can ack/grep on the command line.

The cons are not great for assets such as images.

Looking forward to reading some other solutions.