For me it's very logical but I know it's for many still unfamiliar terrain!! So here is a very efficient plan of action!
Get erect is the first step to take, slide the JBoa over your erect shaft totally to the base, as close to your body as possible is the next. Holding the stainless steel toggle and pulling the silicone cords makes the loop to nicely ConStricts your penis and getting you nearly there. The last very important step now is to push the loop with your two thumps downwards your belly so it sits firm on the spot it needs to be. Now we can only say enjoy your WOOD!!