What have you found helpful when communicating with team members in different timezones?

Being clear about when you need an answer and why (if it’s urgent). Making sure you're providing everything they need in order to move forward with whatever it is they need to do on their side to avoid back-and-forth.

Setting an expectation for when client facing meetings happen - what's the shared time block for those.

In addition to the above, having clearly defined channels for different comms. and the (type of) response (not) required ie email = mostly external, 24-48 hours response time, cc accordingly; Slack is for x, back to you in max 24 hours; WhatsApp text/call for urgencies, <4 hours.