Research, planned out your build, ALWAYS dip your corals! I don't do qt because I believe that ich is everywhere, in the water, in the rock. In the wild, fish are able to fight the ich so they are healthy. Therefore, it is best to make sure the fish eat, and feed them adequately so they are healthy.
Buy decent equipments, by decent I mean not a cheap stuffs shipped from China, not high end expensive Ecotech/ radion, ect ( if you have deep pockets and can afford these then good for you! lol), but equipments in the mid range works best as long as you keep up with maintenance and replace parts when worn out. Get in a habit of atleast looking at your tank's equipments once everyday to ensure everything is running as they should be. And always - IF IT AIN'T BROKE, THEN DON'T FIX IT!