Assuming the model is well trimmed it doesn't matter a whole lot, the main thing is just to be ready whenever one does decide to quit. On my twins I've never noticed any significant yaw issues with either engine out, a noticeable lightening of line tension, but no actual yaw. The line tension seems about the same with either engine out. Mainly, it's just best not to fly your twin when it's windy, which can increase the chance of having a problem.
Here's the simple trick for running an IC twin without a fuel shutoff...
Once at the field and prior to the first flight of the day, fire each engine separately, tune to the desired setting, and then shut off. First one engine, then the other. Don't go for the ultimate lean power setting either, leave them just slightly rich. That "slight rich" needle setting gives a safety margin that greatly lessens the chance of one engine going lean in flight and totally screwing up your chances of them both quitting together, or nearly so. Once you're happy with these prior-to-flight needle settings then top off the tanks and you're ready.
At the flight line, put a battery on each engine, fire the inboard then quickly the outboard. With this routine you should be able to have both engines fired for a flight within a couple seconds of each other. DON'T TOUCH THE NEEDLES, if the engines are pre-tuned as described they will sync up nicely once in flight. With equal fuel loads and the needle settings described you'll usually only end up flying a couple laps on one engine, no big deal.
Whatever the case, ALWAYS start the inboard engine first, you don't want to be reaching over or around a running outboard.