I have not flown a twin but I was going to build and fly an Invader a few years ago so I did a lot of research then. The one main thing I came out with was learn to fly dead stick and set your fuel system up so that if one engine dies the other one will too. You will get lots of arguments on this but that was my take away on it. Luckily I had a lot of dead stick experience so it did not seem like an issue to me.