Here is a how-to Balloon Bobber (Float) fishing set up. 

I know you all have seen slip float rigs before, but this one has several advantages over the standard dink float setup. First and foremost, you can fine tune your float size to the cannonball for each river situation. Second, the extra floats are deflated and eat up little space. Third, if you do not have a second rod, you can quickly discard the float and switch to a drift presentation. Lastly, the balloon acts as a bungee, so the fish do not feel the weight of the setup as readily as with a standard slip float setup.  

Of note, the bobber stop is made by cutting a 12” piece of 15 lb. mono line, then creating an overhand loop and setting it on top of the main line and running one end of the mono around the main line and through the loop four to five times and then tightening it.