Lighting, Light Fixtures, Ceiling and Exhaust Fans - Wiring my ceiling fan

I have been doing basic light fixture and ceiling fan wiring for quite some time now, but have concerns since reading some of the threads on this site on the subject. Each time that I have replaced a ceiling light fixture with a ceiling fan/light duo the wiring coming from the ceiling has always been 1 black wire and 1 white wire. I would simply put black w/ black, white w/ white and attach fan ground wire to electrical box (metal) with screw. If the ceiling fan had the blue (light) wire I would also attach it to the black wires. I've never had a problem with this set-up and fan/lights worked great. I guess I'm started to second guess this application because I have read that many newer style wiring involve a red wire that would be used to run with the blue light wire. I have a lot friends that ask me to install these simple fan kits all the time and I have felt comfortable doing so up until now. I know my limits when it comes to electrical work, so is my practice okay or have I simply been lucky that nothing went wrong?

When they speak of a red wire it is because the house wiring has a three wire coming from the switch -red black white - black constant hot , red switched hot , white to white - so the red would go to the blue so the light may be switched at the wall

Chris, did you realize that the electrical box supporting the fan must be rated and listed for that use?

I just installed a Harbor Breeze model from Lowes. I'm sure the quality of the fan itself is fine. But the directions need a lot of help. Also, they need to be printed separately in Spanish and English. The way the Spanish interpretation appeared immediately with the English was very confusing to me.
Regardless, thanks for the tip concerning the blue wire. The directions did not paint a clear picture for the scenario of no blue wire in the house wiring.

Jay