Wow. It's such an effective tool and it's so simple, too.
1) So, basically get a page made for your custom 404 page. Make it however you want.
2a) If you have a file called
.htaccess
Then skip the next step.
2b) Okay, do this if you don't have
.htaccess
already. Make a new file and name it as that. Simple.
3) You only need one line in the whole thing and it's this:
ErrorDocument 404 http://www.yoursite.com/custom_page.html
It's case sensitive so I recommend you just copy/paste it into your file. Change the http:// blah blah blah to where ever your custom 404 page is.
4) Upload it.
5) Profit! You should be done, but if you come across any errors, follow the link below to the bottom and do that step.
http://www.pageresource.com/zine/custom404.htmThat's where I got this info.