i am one of those guys who likes the 18 and 19 year olds. i am also very careful to weed out the **** ones, and if i have any doubt i avoid them. there are plenty of actual 18 or 19 year old out there available to fill anyones dance card.
i used to do alot of hiring, so i became pretty adept at getting need info from prosopects without their realizing i was getting it.
there are alot of proper reasons for an employer to know the exact age of a prospective employee, yet the usa makes this practice illegal. but you still need to know. many **** girls need a meal ticket, so they may be motivated to lie to you. this you definately need to know.
anyway, before meeting a girl, ask a bit about her life in an interested fashion, not as an obvious cross examination. ask how many siblings, she where is she in the birth order. is she working or a student. buried in there should be a question when she graduated high school. for many westerners, this can be a point of confusion becuase graduating from high school usually happnens about 18. however, in the philipines its 16. so, if she proudly says she graduated high school 1 year ago, bingo, she is probably 16 or 17.
i usually will attack this point from several different angles. if she says her oldest sibling is 20, and she theirs 2 sibs inbetween her and the oldest, red flag. if she says she's a college student, ask what year / level she is. they generally start college at 16, so you can extrapolate from there. if she has a job, ask how long she's had it, etc, etc. the point is to develop a timeline and check it from a few different angels. most people, even smart sophisticated ones (and most of these girls are neither) are incapable of developing a false profile that covers every party of their lives.
this technique can and does uncover any red flags and discrepancies, and has the added benefit of making the girl feel your interested in them, which can help their performance in the sack.
if they are gf or regular potential, offer to pay to get them their passport. this will set you back about php 2, 000. any of age filipina will jump at this opportunity, because they hope you will take them on trips outside the phils, and it also gives them to option to become overseas workers. i also like this option because it helps me weed out the piso pumpers. if you know the cost of thing in the phils in advance, and you offer to pay, and she gives you an inflated price, thats a really bad sign. if she gives you the correct price, its nice to know you have an honest one. anyway, to get the passport the nbi (phils fbi) will do a very thorough backround check and she has to present a birth cert and good i'd. no way around it for her. if she doesn't want the passport big red flag. if she already has one (not likely, but possible) then its simplicity itself to ask to see it.
anyway, hope this helps someone.
happy hunting