I have found that a good age is about 24 - 28. They are still young and firm plus they have some experience with technique.
But nothing beats a firm 19 year old if you find one, you almost forgive everything else for that!
Ditto. i tend to avoid searches for 18 yo, but have considered 19. Many are actually a bit older than stated age on AW, and I'm aware of need in law to avoid under 18's also, so only do this with girls i am sure meet that requirement.
I would say, punts with under 24's are not going to go as well as those who are over 24 - for reasons of their maturity and experience, in the main, of course, there can be exceptions - indeed my very best WG I've seen (of all time) was 23 (she said she was 21 on AW!!), so for me, its not a hard and fast rule, but one I cannot deny is generally the case.
I was with a WG recently, who said she regretted not starting a little earlier - when i asked what age she would consider starting, she said 23, on discussing this in more detail, it was very clear that for her, she would never have wanted to start before that age, for reasons we have discussed on here, primarily general maturity and feeling confident to be 'independent' For info, she began 'working' at 27.