Tools for use in making tools eh? what a strange topic you may think, but I have a few things whcih I use daily which save tons of time and I wanted to share and maybe find a few more tricks from others.
Here's my top 3 for our current project:
directfolders - this is worth its weight in gold. Somone on polycount reccommended it afaik and it has been so useful for speeding up moving files around and general opening of stuff in different apps as you work on it. Sure beats a ton of folder shortcuts on the desktop which I used to have.
total commander - So useful for syncing folders, multiple renaming and so much other stuff I cant explain. 2 side-by-side file explorers for me is worth the price alone, a great weapon in the tech-ish arsenal, even if it's a bit like swatting a fly with a sledgehammer for lots of day to day stuff.
and finally, possibly the coolest one - apparently like some software on the mac, whatever that is... but it is seriously handy, you can associate it with any extension and give it different folders. I can run our engine with a tappity tap while keeping all my windows up and keep working, or use it to open up web pages, text files, run batch files any old thing really. A nifty tool for sure.
Anyway, they have shaved days off the schedule if not weeks and I'd be interested to see if anyone else uses any of these sorts of things in day to day work.