Try experimenting with different types of shavers too...
Stick to using an electric shaver and pull any skin that has hair on it... If u stretch the skin u won't cut urself and it will run along smooth... I shave my balls with an electric shaver and I have mastered not cutting myself to this day. Do take time n don't rush. I find if u have an ercet penis at times it can be easier to shave but to answer ur question about all areas just use a big enough mirror to be able to see what ur doing. When I shave my face using a different electric shaver I pull the skin streching it over and along the chin where sometimes u find when running ur hand over ur chin u still feel stuble. Pull the skin for a smoother shave. BEST OF LUCK.