Give your clients alerts. Send me a text message 15 minutes before the appointment, if its time and you've been waiting for 5 minutes call me.

Yes I know I can set up calendar alerts, but odds are I screwed that up somehow, and a call will get through.

Bonus points for telling me not to feel bad and stress too much if I'm late. If it's an hour appointment and I joined 30 minutes in, that should be okay. Yeah I've lost the unused time, but otherwise that would reduce my stress.

Also I'd rather have a change under 24 hours, be accommodated (if it's possible on your end )without an extra charge.

I can definitely see myself the day before "going wait can we move our 3:00 to 5:00 instead? And if that's not possible I may just want to keep 3:00, but if it works for everyone I'd rather have 5pm"