You begin by building your frame.

Then, you will add the panel door centers.

How To Make Frame And Panel Cabinet Doors - Easy Cabinet Doors - How To make Cabinet Doors

Image By: Steve Ramsey – Woodworking For Mere Mortals

Easy Carpentry Ideas - How To Make Easy Wooden Cabinet Doors - Learn To make Cabinet Doors

Fun Woodworking Ideas - Cabinet Doors Made Easy - Wood Panel Doors