Where ever you go look at transport options where you may be able to tie in travel and sleep - can save on accommodation.
If you are planning on going travelling for several months it may be worth investigating places where you can pick up seasonal work on a visa thats relatively easy to acquire so you don't have to worry about saving for the whole time you are away or avoiding doing things because you don't quite have the cash.
For places like Europe (east or west) you may find it useful to pick a couple of places to base yourself where you can get to lots of destinations without constantly carrying your pack with you. That may give you the opportunity to look for cheap accommodation over a couple of weeks, get familiar with a country and the people and still visit a lot of places.
Don't pack for the trip pack for events - weather, tourist attractions etc. Bear in mind that layering up is better than lugging about bulky jackets or coats and means you are prepared for any climate. Lots of religious sites wont let you in if your shoulders or knees are exposed so long shorts or a skirt and a light cardigan/shrug etc are useful to have with you.
If you are planning to visit destinations in their high summer or winter time investigate what kind of weather they typically get and either budget to buy the right layers for that place or consider your options on easy to carry layers to be appropriately and comfortably dressed.
Never flash the cash! If you are carrying all your money with you don't carry it around in an easily accessible wallet/purse/pocket. Only have available that days spending money so if you do lose it you aren't completely stuck. And remember fellow travellers can be as tempted as the dodgy looking locals so you need to just practice care.
Its also worth remembering there are people out there who see you as a meal ticket. The trick is to not be the easiest target. Don't wear wildly valuable jewellery or expensive high end items (in poor countries especially), don't disappear down alleyways to check your gear or a map but perhaps go to a cafe or into a shop, and if you don't feel comfortable in any situation remove yourself. Its always worth sticking to busy public places even if they attract pick pockets - at least you are seen and heard easily!!
Best places I've ever been: Italy, Spain, South of France, Scotland, Thailand, New York!! I'd love to visit China, particularly the north, and Vietnam is supposed to be utterly amazing.
Have a good time!