Food scales are
fantastic for home cooking. Thanks to the tare setting, it's ridiculously simple to make just about anything--weigh it all as you go, then divide it up into serving sizes after preparation using the same scale.
They aren't much help when you're outside of the house, though, so I also find it useful to train myself to estimate portions. Visual guides like
this one help internalize what a proper portion size is.
I'd definitely scoop up a nice food scale, though. They are sooo useful. Also, it's fun to weigh random stuff; puts me in touch with my inner mad scientist.