Common sense accessibility 2.0

When it comes to accessibility, every coder is a small guru. On the websites where I bid for projects everybody is an accessibility and usability expert (including myself, I admit). Altough these rules exist for quite a while there are coders who find difficult to implement them - so I am trying to find here what are the tricks that you use in writing your code to make it accessible. For example, although writing semantic code helps (a lot !) it is not always enough. Some try to view their pages with CSS and images disabled, some don't. Some of us have tricks that we do not want to share to other coders. Some of us share. We're not all gurus, right? Someone has to start from somewhere. So if you have something interesting to say, add your own rules here.