As a plugin developer, one of the most time-consuming aspects of development is putting together admin panels. With the effort that goes into this end of the development, you want your admin panels to look slick and professional – you want them to integrate seamlessly and look like they belong to WordPress.
A good way to make this process easy, is to use the WordPress Admin Style plugin from
Frank Bültge and available on GitHub. The WordPress Admin Style plugin makes it easy to see the different classes and HTML structures of the WordPress Admin by laying them out on the screen in logical fashion and including the name of each attribute.
It is an unfortunately uncommon Best Practice to not use your own styles and instead use the WordPress tags and classes. This plugin will make that process easy for you to look up a particular style so you can develop a more flexible plugin. Think about it. If you use your own style in the admin, how many times have you had to change things when the look/feel of the admin changed with the new version of WordPress? For that reason, I would say that this is a must have plugin for plugin developers.