My own code that's common throughout all of my software.

Report writers, data base update objects, data formatting routines, form processors, string & array handlers, special logic algorithms, and especially, code generators.

The more I read these, the better I know them.

The better I know them, the easier to improve and extend them.

The more I extend them, the better my software gets and the less of it I have to write to get anything done. Leverage.

I literally have a folder of all this stuff on my nightstand or in my backpack all the time.