Say NO to everything that does not support your goals.

Say “But I’m on a deadline right now, and I’m not taking any meetings until I’m done.”
Use this response with strangers who cold-contact you.

Say, “Unfortunately, my schedule is so packed at this time, I can only take calls and meetings with paying clients.”
Use this response for people looking for free advice for themselves and their companies.

Say “..., and I’m happy to connect, but there is no daylight in my calendar until ….” (Pick a date five months in the future.)
Use this approach for someone you don’t know personally but who is vaguely connected somehow.

Say, “... and my next open slot for a phone call is 2:00 - 2:15 am on Thursday next week.”
Use this approach for persistent people. The possibility they will be up that late to call you is slim.

Say “... but I don’t think I’m the best person. I will like to refer you to someone who can handle your needs.”
Use this approach for those who request your time because they think you know something that can help them or think you are a decision-maker.

Say “... but I cannot take any more meetings or calls during normal business hours. But often, I can catch up on emails during my travels or at night. Would you like to communicate via email?”

Say “... and as a rule, I only schedule 15 minutes for first calls. If you are interested, could you send over a draft agenda so I can see what we will be covering and what desired outcomes you are hoping for?”
This type of response is a good way to let others know you are busy if you don’t want just to reject the person.