Feel free to reply with your own points.
1. Content. Your site sucks and is a waste of space and bandwidth if it is yet another godawful anime, general computer help, or other useless redundant pointless site.
2. XHTML compliancy. Absolutely never rely on a certain browser, so make your code XHTML 1.0 Transitional compliant (http://validator.w3.org/). This means that at this point, it’s the browser’s fault for not rendering your page right, not yours. Explosively gaining popularity browsers such as Firebird strictly adhere to these specifications. Be CSS compliant as well.
3. Remember that millions of Americans are vision-impared. That means never rely on color to convey a point, use large font sizes, and avoid text in images wherever possible.. ABSOLUTELY NEVER use a light-on-dark color scheme…it’s murder to view on some monitors and with some vision impediments.
4. Absolutely never rely on browser extensions or client-side scripting to make your page. That means avoid Flash, Java, and Javascript wherever possible.