I've been reading many posts here on the helper thread. Many problems seem to be that people have unrealistically high expectations -- that a helper will know everything and transform your life. And that employers don't ask questions BEFORE their helpers get to Hong Kong.
The guy at the Arrow Agency gave me a few tips -- like making sure that the helper can answer questions in thoughtful, detailed sentences, instead of just "yes ma'am" or "no ma'am".
Two questions we asked.
* "If there was an emergency -- like baby was really ill and both parents were at work, what would you do?" Some of the younger candidates had awful answers, like "check his diaper." The mature ones knew to pick up the phone, call the parents, ask in advance for a phone list, call the building management, call the doctor, etc.
* "What are your strong and weak points?" The helper we ended up hiring was very honest -- she said her strong point was childcare and education. Her weak point was cooking -- which is not a skill we need so much. But at least we weren't surprised when she got here.
* We also asked detailed questions about exactly what work she did or did not do for her past employer.
And, of course, check references. And be very clear exactly what you want from the beginning -- a young energetic helper? An older more stable helper? A married mother? Someone with good English, or cooking skill, or baby experience? No helper is going to excel equally in all areas.
Good luck!