The goal of accessibility is to design & code digital products, services in a way that users with disabilities are able to use them. Your context or temporary condition and limitation also affect the way you use a product.
In this article, Tom Stevenson shares some of the tips and tricks he used to move his blog from a few people reading it every day, to over 2,000 today.
Jakob Nielsen's 10 general principles for interaction design. They are called "heuristics" because they are broad rules of thumb and not specific usability guidelines.