Category A: High importance, high urgency Do them yourself now. Within reason, spend on them whatever time they take.
Category B1: High urgency, low importance Consider delegating these as a development opportunity, perhaps to a new team member. Get them done soon.
Category B2: Low urgency, high importance Consider delegating them to a reliable and experienced member of the team. These tasks need a ‘safe pair of hands’. Remember to schedule a time for completion.
Category C: Low urgency, low importance Delegate these tasks and schedule a time in the future for completing. Keep an eye on them.