Delegating is hard for some people. I am one of those people (which is, I know, not a great quality in a project manager). The hard part for some people is a loss of control. For me, it was always a fear that they won’t do the task right. It took me some time to figure out that often when the person I delegated to didn’t meet my expectations, it was because I failed to communicate what was needed.
If you want to delegate well, don’t set your delegatee up for failure. Set expectations. Define the task completely. What is the expected deliverable? What is the due date? What is the budget? What resources are available to help? Supply a template, example, or even a simple sketch to help identify your goal.
If you don’t explain what you want, how you want it, and when you want it by, then don’t expect what you asked for to be delivered. Every PM knows this. Put it to use in your every day life.