"shut up, gracious, prevent defense"? Of course not. However, and just off the top...
"Presidential, principled, dignified, and Reaganesque" would be worthy objectives for our nominee.
Being Reaganesque was great for Reagan. That’s who he was. But Reagan’s not running. Better advice to any worthy candidate is to be yourself and not pretend you’re something you’re not. The people want and need honesty, not nuance.