I use this one before I start cutting.
http://www.amazon.com/TrueCut-TCSHAR...0950585&sr=8-1 I always sharpen a sharp blade. I have the second one for when the blades won't hold a sharp edge for a day's cutting.
http://www.connectingthreads.com/Too...r__D81995.HTML
I am very happy with both sharpeners.