By far, one of the best investments a photographer can make is a pressure-sensitive pen tablet. They can make a huge difference in your editing workflow, both in terms of precision and efficiency. This great video illustrates why a tablet can be so useful in a photographer's workflow.
Coming to you from Matt Kloskowski, this excellent video discusses the benefits of a pressure-sensitive pen tablet for editing photos. If you have not used a pen tablet before, they are incredibly useful, as they allow you to use a more natural drawing motion to edit your images as opposed to using a mouse. Beyond that, they also offer a range of features that your mouse cannot, with one of the most notable being pressure sensitivity. This allows you to tie an intuitive physical touch to common parameters like brush size and opacity, allowing you to set up behavior like applying more of an effect the harder you press. There is definitely a bit of an adjustment period when it comes to using a pen tablet, but after a week or so of consistent usage, you will probably not want to ever edit with a mouse again. Check out the video above for the full rundown from Kloskowski.