Hairdressers have, understandably, massively hiked their prices since lock down. During that time we moved, so looking for a new hairdresser I hot footed it down to my local salon couldn't believe what they quoted, probably double what I was paying for what I was having done and that was in West London
However, I shopped around and found a satisfactory local hairdresser and now have my foils done every 5 weeks, I've upped that time span since I dropped my base colour and embracing the grey blending with the highlights. She did say, that appointments for such things have fallen off a bit since the cost of living hike and is thankful to have regular appointments such as mine. To get to the point, I tip her more than I would have done at Christmas, and I gave her some $ notes that we still had when she took her children off to the US at Easter, but other than that I don't, I did prior to Covid but I have massively upped my spend on hairdressing on more regular appointments and I spend quite a lot when I go.
As for restaurants, some such as Cote take 12.5% service charge so they take the option away of leaving a gratuity but we would if that wasn't the case, particularly when we've had good service, similarly if we take a taxi to the airport again we would tip.