As of late, I have one rule: Any unknown number I'm not expecting I let it go to voicemail, where I have a message along the lines of: leave your message and your number, and if it's important I'll call you back. The only time I pick up is when I am expecting, say, a delivery, or a doctor's call, etc, and in those cases I'm only expecting to hear about a delivery or a doctor's call, etc. Hoping that can filter and help on this front.