1. Look simple. If you can look poor, better. Dress comfortably.
2. Do not speak English at all costs. You will soon realize that things cost more if you speak English or speak Tagalog with a twang. Pretend to be mute if you belong to the latter category.
3. Bring lots of change. Do not pay using large bills. It would be to your disadvantage if you appear to have lots of money. This will also make you less â€œhotâ€ in the eyes of some bad elements in society.
4. Have lots and lots of patience. Browse through all racks. You might miss out on a great item if you donâ€™t.
5. Bring a large plastic or shopping bag. You can stash your paid items here so both your hands are free to browse through the racks or grab items.
6. Buy items on the spot. Chances are they might not be there the next time you come back.
7. Do not make the mistake of asking if they have sizes.
8. Grab items you want and do not let go till you get to the cashier even if you are unsure about them. The moment you let go of an item, somebody might just be waiting in the wings to grab it and when that happensâ€¦sighâ€¦let go. Never get into a fight with somebody over an item that you let go of earlier. In the ukay-ukay world just like in normal retail, once you let go its up for grabs. It is an integral part of shopping etiquette.
9. Bargain, bargain, bargain! P10 is still P10 – good enough for a lot of things.
Source : http://www.shoppingera.net/2006/02/05/ukay-ukay-tips/