Once you get the angles on your blades.....a simple piece of 800 & 1200 wet/dry sandpaper glued to something flat work out great! If you read on line references regarding the different rouges you can find out what best fits your needs. I own all of the colors, but I mostly use the green bar from Leather Wranglers. I have a dedicated strop on my bench and in the garage, but like it was stated, you can use a simple business card or poster board.
Good luck!