Choose a strong rug sack that would feel comfortable when you carry on your shoulder. The rug sack should have many compartment so that all your stuff can be organised properly.

Packing light is highly recommend for all travellers, packing light not only helps you move around with ease but also lessen the load on your shoulder. Pack only what is necessary for your trip, you don't need a lot of clothing (clothing usually make up of most of your load) when doing backpacking, as you are expected to do laundry pretty often. Travelling during the summer requires less thick clothing, usually a good windbreaker would do, while travelling off summer season, might require a piece of warmer lothing, excessive would be a burden.

Check weather condition around your destinations before you start packing. Climate in South East Asia is always hot and humid all round the year so prepare to do lot of laundry as you will be sweating a lot. It is also a good idea (if possible) to leave your rug sack half or ¾ unfilled, as you will be expected to buy lot of goodies, while travelling. This would help you to move around, especially arriving in busy cities.