Dear America - How much is the tip?

Whilst it seems like such a little thing, tipping really throws me. It’s not the calculation - I can work out 10%, 15%, 20% and even 25% in my head like most people who passed grade school maths (heh - you see I am turning native - primary school math for non-Americans). It’s the etiquette of it. Americans grow up knowing what the appropriate amount to tip is and when a tip is appropriate. The rest of us have to puzzle it out. And it’s not easy. Here are some of the key challenges:

1. How much should you tip percentage-wise?
2. Who do you tip? All waiters? Doormen? Concierges? Bus-people?
3. What constitutes good service?
4. How do I know if a bar, restaurant or a hotel pays tips to their staff? Especially if you Debit/EFT a charge. If I add an extra tip in a Hyatt does the room service waiter get it?

Add to this the inherent Australian (or is it just me?) awkwardness about pushing money into people’s hands - like hotel staff who carry your luggage.

I’ve slowly been ape’ing Americans and asking questions about it but am I asking the right Americans? What if I have latched onto the cheapest Americans ever?

Tricky and a slightly stressful minefield every time we go out.