Don't provide ergonomic chairs, desks with keyboard drawers, good lighting, or adequate desk and storage space. This one can cost several hundred dollars per person. Don't encourage technicians to put their phones on do not disturb when they are concentrating on a task. Don't focus on design to simplify implementation. Don't practice risk management.
Nothing drives away technical people faster than fear, uncertainty, and doubt.
Therefore, you should try to create as much FUD as you possibly can. Work diligently to keep technical people out of the decision making process. If your company is going through a restructuring or a merger, don't let technical staff know what is going on. Make sure to use an intimidating management style. Delay annual reviews for as long as possible.