The ye old saying of changing your oil every 3,000 miles or every 6 months doesn't apply that much anymore with our modern cars and technology. I was always taught that when you change one fluid, change them all. That way you aren't fixing something that will be broken again soon anyways due to the wear on another thing.

What are yall's general rule of thumbs concerning your fluids? i.e-engine oil, trans fluid, brake fluid, coolant, power steering, etc...