I recently returned from a trip back to Asia, taking in Singapore and Philippines via Doha with Qatar Airways and then Scoot from SG. Masks were required to be worn on all of the flights except when eating or drinking, this was enforced more on Scoot than QR. In airports, it was not enforced except in Clark in Phils.
At check in for Singapore in London, proof of vaccination at check in was required but no pre-departure tests or any on-arrival tests were needed for either place, straight out after completing the necessary immigration etc. Same on departure, no tests needed. At Changi at check-in for Phils, had to show the Gov health app to prove i'd been registered for arrival, had to show proof of vax status at security on arrival.
In Singapore there is still a need to wear a mask on public transport and in a medical institutions but not otherwise, generally I reckon about 60% of people still wear them in shopping malls etc out of choice.
Philippines is its generally required for masks outdoors and still getting hand sanitized if you go indoors. It is a bit hitty-missy though, this was Clark airport though not Manila.
I would normally have gone through HK to Phils, but that place is still nuts so SG won. Glad I did too.
All in all, pretty much what I expected, SG was a breeze, would go via there anytime. Restrictions will be further relaxed soon I believe if they haven't already been