When doing an assessment or audit of a site, it is really helpful to highlight links that you need to check out.
For example, many sites will hide visited links, or you might want to see which links are in the current section of the site.
Use the Test Styles bookmarklet from Squarefree, and then the following examples are examples from CSS3 selectors.
Local links
If you can see the folder structure of the area, e.g. you are in the /example/ section then this will highlight links in the same section:
a[href*='/support/'] {outline: 1px red solid !important;]