There is going to be contact from time to time. It shouldn't be intentionally instigated, other than perhaps a touch on the hip, just to say you're there. (although you can debate whether you should take your hand off the bars in that situation.)

Touching bars is inherently problematic. Handelbars interlocking equals spectacular crash. If things are that tight, I'm going to flare my elbows a bit to keep people away from my handlebars.

The trick with contact is realize its going to happen, and not get freaked by it.

Really good drill is to go in a grass field with some friends and practice bumping into each other intentionally, and learn to stay up right.