If you tell others often that you are busy – and genuinely would prefer not to – understand two things.
First, delegating is not about telling others what to do, it is about trusting them with important problems to solve. It’s not about “I need this report by tomorrow” and all about “how and when do you plan to report on the findings?”.
Second, there is no one single thing that will dramatically impact the outcome if it is done today rather than tomorrow. Urgency is fake. Success is achieved by doing something consistently and over a long period of time. Big projects or tasks that pop up at the last minute in your calendar are not going to drive results.
Now go out and practice this.