If possible, work with an existing page that you have created or that you have worked with, and apply each of the rules to it. For each rule, process the page systematically by considering all elements for which the rule might be relevant. This will be easier and more thorough than trying to apply all rules in a single pass through the page.
Use a content page rather than a main page or an index page. Main pages are very important, but they have special issues of their own.
Alternatively, you may take just any web page and apply the rules to it, after making a copy of it. This is not very motivating, however, since you know that the results of your work will probably not be utilized in any way.
Keep a copy of the original page and the modified page. After the testing you normally do before publishing a new version of a page, upload the modified page. However, refrain from doing this if the modifications have made the page structure different from the general structure of your pages. Essential changes to things like navigational menus should of course be made for all pages at a time.
During the exercise, write down a very short description of the changes that you have made. For example, for rule (3), the description might read “added 4 empty alt attributes and 1 nonempty, for the site logo”. For rule (10), the description might be “changed font size from 10pt to 90%.” These notes will help you later when you work with the same sample page, performing additional accessibility improvements.
If you have friend who is also learning accessibility, it is a very good idea to cooperate by evaluating each other’s pages and exercises. This is particularly relevant to the difficult rules, marked with “**” or “***” in the presentation of the rules. Someone else’s evaluation of the simplicity of your language or the adequacy of your link texts often deviates a lot from your own evaluation. You will probably get some good ideas on improving your texts and page organization.
Work on accessibility should mainly consist of more accessible design of new or completely rewritten pages. It is generally not productive to do “accessibility repairs” of existing pages, but repairs are useful for learning the principles and methods. In daily work, the twelve simple rules are most useful as a checklist during design, implementation, and testing.