Learn how to do your laundry

This very detailed post on The Hairpin will teach you everything you need to know about washing your stuff.
It should be required reading in pre-college orientation.
Not joking.

I never knew exactly what was going on with these things, for example, and I had  them backwards in my mind:

Permanent press: a medium-heat dry cycle with a cool down period at the end designed to reduce wrinkling.
Regular: the highest heat setting, best reserved for hearty items like jeans, sheets, and towels

This was also a relief to me:

But first: it's worth saying off the bat that when it comes right down to it, it's not the worst thing in the world to wash cleaning rags along with your clothes. Machine washing is pretty serious business, with multiple suds-ing and rinsing cycles — more or less no matter what you put in, dirt-wise, things are going to come out clean.

.