2. don't post a lost message to radio broadcast (some told me if drivers know you are willing to spend money doing it, the possession must be very "useful" or "worth some money"
3. Remember you could always claim against home content insurance policy if that possession is worth considerably more than the deductible.
My previous experience was I left my mobile (which only cost several hundreds). And it was returned upon I agreed to pay the taxi driver HKD100 for the transfer. My message at the radio broadcast very close to the time I left the taxi, that's why I was willing to pay. But still....bad luck with a driver.