You can display a custom 404 page to be more helpful to a user and provide guidance on what to do next. For example, for the Apache server, you can specify a path to a custom 404 page in an
.htaccess
file:
ErrorDocument
404 /notfound.html
For an example of a custom 404 page, see this
404 page
.
Note:
Custom design is a good thing, in moderation. Feel free to make your 404 page humorous and human, but don't confuse your users.