I live, work and play in Asia. Here are some of my tips and suggestions for travelling here.

Tickets

Troll the internet for cheap tickets and keep your eye on specials. Airasia.com is an excellent site for both accomodation and flights. Areas that are particularly cheap to travel and stay in are Indonesia (not Bali so much). Cambodia and Lao, You can routinely get rooms in these places for less then $ 15 US a night

What to bring

Suncscreen ( it is often expensive-relativily speaking in Asia and you wont be able to get the brand you like)

Prescription drugs

Tampons/pads if u are a lady they can be hard to get and you wont be able to get your brand

Baby wipes for washing hands before eating

Appropraite clothing for the climate/culture

Toothbrush and paste  

Good guidebook ie lonely planet or good internet  research

A laptop/EEEPC (there is lots of Wireless around in Aisa)

What you can buy there:

Soap (often supplied in the guest house)

Shampoo/conditioner (bring your own if fussy if not... try local)

Alcohol (often much cheaper particiclaurly Laos)

Things to do:

Have massages.. at $5 US why not have 2 a day?

Eat Local food- often I eat at dodgy roadside stalls, watch the locals if its busy and hot you will probaby be ok. As a precaution I buy Yakult drinks and take 2 a day, I dont usually have a problem)

See the sights ie Ankor, Museums, markets, go tubing in Viang Vieng

Tips

talk to other tourists to ask what sort of prices they are paying

Only hire taxis/tuk tuks that are moving not touts that are harrassing people by the side of the road real taxi drivers drive!

Use buses they are an adventure

Keep hydrated... 2 litres of water a day.. more if you are walking

Dont drink and drive if you hire a vehicle yourself

Ask before you take a picture

Stay in guesthouses... not five star hotels... they are cheaper and more fun! 

Be adventurous, if unsure think what is the worst thing that can happen and if the consequence is livable... do it