Create Meta Boxes for custom plugin
So you have just created you Wordpress Plugin Admininitrative page huh? But now that you got the functionality you were looking for working and you'd like to style it Wordpress style. And while you're at it you would like to make all your boxes to be just as flexible as all the Wordpress Dashboard widgets. I mean you want people to be able to move them around and fold them when they want to right? Blend them in, make them part of the whole Wordpress Dashboard.
Styling your plugin administrative page
So you start styling all your boxes using the appropriate Wordpress classes and ids
Turn page's boxes into Wordpress widgets
So you styled your admin pages boxes, but guess what? The boxes won't close! Nor can you move them around like you can with all the other boxes! Why? I mean you didn't change anything in the Wordpress admin nor did you delete vital files.