There seems to be a bit of a cultural divide when it comes to the phone, and I’m prepared to be called out as a “young person” writing this. My philosophy is you see, that you don’t always have to answer.
There is something fundamentally off about calling people. We always (if we are polite) start off asking if you reached someone at a good time. The presumption is that we are disturbing them. And you know what, we probably often are.
Most people would argue that they are busy only when they are in a meeting, or doing something in the company of others (and sometimes not even then). I take a broader approach, and I think you should too.
For example, if I am sitting in my office deep in thoughts and working on a project and someone calls, I don’t always answer. That’s not rude. That’s just me being busy.
If you really want to be sure to reach me, you should go ahead and schedule a time to talk. That way I can give you my full, undivided and prepared attention. But don’t expect me to always answer when you call and haven’t. I have to protect my time to be effective.
So what should you do when you call and I don’t answer. Send a text or email and let me know what you want to talk about and I will definitely get back to you. The key there is letting me know what you want to talk about. That way I can prepare and talk informed. That makes for a great call.