A common problem with comments is spam. Sure, you can moderate comments and use the Akismet plugin. However, sometimes someone leaves a normal comment, you approve it, and then the spammer—who knows that his comments aren't being accepted by the moderator—starts to spam your blog.
Even though you can do nothing against this (except moderating all of the comments), a good idea is to either add spam and delete buttons to all of the comments. This way, if you see a comment saying spam while reading your blog, then you can edit it, delete it, or mark it as spam. I got this useful tip from Joost de Valk, who blogs at www.yoast.com.
The following screenshot shows normal comments without the edit, delete and spam buttons:
There's nothing complicated at all with this recipe. However, you must be sure to know which kind of blog the users are allowed to edit or delete your comments. For a list of actions and user roles, see the section named Controlling...