A bit of travel advice on money is always useful! Deciding how much you'll need on a trip isn't rocket science - but it isn't all that easy either.
Your decision will depend on a number of things: the kind of food you like (vegetarians will spend less than carnivores), your drinking habits (you'll save money if you don't drink), your ideal sleeping arrangements (compare a tent in the wild with a four-star hotel), the length of your trip, and your destination - you won't spend the same money each day in Paris and in Bangkok.
My first step is always to make a travel money checklist that lists everything I think of that is financial in nature, including how much I think I'll spend. It will never be absolutely exact because things change as you travel, but it will give me a good head start.
There's not just what you'll spend on the road but what you need to spend up front, before you leave.
To help your budgeting, here are a few examples of what each of the world's regions could cost you each day in US dollars. Remember - this is budget travel at its best: for this amount, you would sleep in a hostel, eat at street stalls and markets, and get from one place to another on local transport (and sleep on board when you could). It does not include alcohol, going out, sightseeing and any other extras. I use this as a rule of thumb and then add 25% as a safety margin.
Southeast Asia - $25-35
South Asia - $15-25
East Asia - $25-35 (Japan over $50)
East Africa - $20-30 (add $100 a day if you go on safari!)
Northeast Africa - $20-25
North Africa - $25-35
Southern Africa - $30-40
West Africa - $25-50 (prices vary wildly from among countries)
Australia/NZ - $40-60
South America - $20-40
Central America - $25-40
North America - over $50
Egypt - $30-40
Syria, Lebanon, Jordan - $20-35
Turkey - $40-50
Gulf States - over $50
Western Europe - $55-$75
Eastern Europe - $30-50
A word of warning: In some places these travel costs won't be enough, for safety reasons. This is especially true where it's simply not possible for a woman on her own, for example in a low-end hostel in a riskier part of town. Most often this is not the case, but be forewarned - if the region you're visiting on your own is unsafe, plan to stay in a more secure - and therefore more expensive - hotel.
You'll also have to contend with additional costs - safari entrances, canopy tours, cookery courses. You may not know how much each of these activities will cost, but I tend to budget $100 per activity. They may be cheaper but this keeps me in the ball park.
Once you've figured out how much to take with you, you'll have to decide how to take it with you. There are plenty of ways you can carry your money - from prepaid credit cards to travelers checks you can cash along the way.
And remember, you can always stretch your money... You can consider overseas jobs as a way to earn money on the road. You could also sign up for volunteer work overseas: not only will you be doing some good and making a difference, but if you volunteer locally, chances are you'll be able to stay with a family in the longer term at very little cost. If you do continue to be a paying traveler, there are plenty of budget hostel accommodation options along the way.
I left home for a one-year RTW trip with $11,000 to my name. I ended up traveling for three years on this amount, working my way as a writer (with a few less glamorous jobs thrown in). Had I run out of money, I would have simply come home sooner. That's the beauty of an open-ended trip: you stay on the road only as long as you want to - and as long as you can.