To avoid missing out on important items, it will be a good idea to prepack your backpack ready-to-go in Hanoi as you have only about 2 hours upon arrival from the train station before you start trekking. Bring spare locks for your main lauggages and your backpack.
Clothing/Shoes/Weather Gear: Sleepers can be a common hall or private room, comprising foam bedding and mosquitoes net. The bedding seems clean enough, but if you are concern about bugs, a good idea is to have a silk sleep-sack to keep any crawling bugs away. I had a poncho, but did not see the need to use it. I brought mosquitoes repellant and anti-bacteria gel but didn’t notice any mosquitoes (perhaps was too cold in winter).
Essential items to have for the trek are some layers of warm & light clothing (morning can be cold but get pretty warm during the day as you trek), a torchlight, hand towel & toiletries, spare clothing and socks (I ran out of socks & clothing to change on my 3rd day as my washings couldn’t get dry in the cold and damp air. A pair of sturdy trekking shoe is essential but trekking stick is optional.
Toiletries and Medical Supplies: December is cool and dry, which is great for trekking. Drinking water and food are widely available in villages. Homestays that I stayed have clean but basic hot shower, flush toilet with toilet roll and power socket for recharging your phone and camera.
Photo Equipment: Bring your chargers for camera, handphone, Ipod etc, but bring along an adapter if your power oin is not a 2-pin power pluck.
Miscellaneous: Dinners are mostly stirred fried greens, tofu, and meat and of course rice wine. I found the food delicious especially the garlic French fries. Breakfasts and lunches are light – loaves with cheese and greens or instant noodles. You may wish to bring your own food to complement what are been offered. I brought along a can of chilly tuna and several energy bars. Bottled water is availalble in villages, and your guide will provide you with one each day.