Have you troubled with the default clipboard system which cannot contain multiple texts at once.
Overwriting the content of clipboard with the other text accidentally.
Clipple provides the extended clipboard system to the Firefox, which allows you to store and paste multiple texts.
It's easy to use. You doesn't need to do special. Just copy text as always.
The only thing changed is that you doesn't have to care of overwriting the clipboard content.
Paste phase is also easy. Right click on the input area and select "Clipple - Paste". Texts you have copied will be listed, then choose the text you want to paste.
If you are the keyboard junky, use extensions like keyconfig, KeySnail, Vimperator to bind the function below to the certain shortcut key.