Get the largest tires that will fit and slightly lower the pressure. Also look for thinner, pliable tires, or at least tires with soft sidewalls. The flats one gets from lower pressure are pinch flats or "snake-bites" where the inner tube gets pinched between the rim and the road because the tire didn't support it.

My main commuter, a 2015 Charge Plug, came with Kenda "Small-Block 8's", a sort of micro-knobbie. Not a great road-tire tread-wise, but very soft and comfy. Right now I am enjoying the most comfortable of the 4 different pairs of tires I have put on my Plug; 700x35 Forte Metro ST Tires, $12/each on sale at Performance Bicycle, normally still only $24 each. I ran them at 75psi and they were very, very plush. I now run them at 90psi as that feels best to me. They're basically slicks with a hint of siping. Dry pavement, dusty pavement, sandy, gravel, dirt and rain, they are still grippy and secure.