making Firefox save my tabs before I quit
 

If I have multiple tabs open when quitting, Firefox offers to save my tabs. I usually don't want it to, but I haven't checked "don't ask again" because occasionally I do want the tabs saved. Is there any way I can manually save the tabs when quitting, which would allow me to click "don't ask again"?

You may like to look into the "Session Saver" extension, and/or the "TabMixPlus" extension. A carefully crafted combination of both can do what you want, and more.

Sasha