Most people delegate badly for one reason: they hand over a task without saying how much decision-making power comes with it. The other person then either asks permission for everything or makes decisions you did not expect.
Make the level of authority explicit. A simple five-level scale works well. Level 1: do exactly what I describe. Level 2: research the options and report back; I will decide. Level 3: recommend an option; I will approve it. Level 4: decide and act, then tell me what you did. Level 5: decide and act; no need to report.
Choose the level based on the person’s experience with this kind of task and the cost of a mistake. A new team member handling a client complaint might start at Level 3. An experienced colleague ordering office supplies can be at Level 5.
Agree on the level when you hand over the task, and raise it as trust builds.
Try this: list three tasks you delegate or plan to delegate. Assign each a level from 1 to 5, and tell the person responsible which level applies.