I've known Maruo from Reed Geek for ages. With one of these tools in his hand it's like a magic wand. I've never met anyone who is more adept at fixing reeds.
And this is his tool of choice. This, along with the reed polishing cloths, with practice, means you'll get many, many more reeds working out of that box. The key here, of course is practice.
Below are some videos that Maruo and his friends made to get you started. I think they're useful. (Though, please note I do not recommend working on reeds while they're on your mouthpiece, and there are some scenes where he does this. Don't. One slip and you'll be looking for another mouthpiece.)
Once you have the reed the way you like it, finish it up with my polishing cloths and you've got a reed that should last a long, long time.