Most trips are planned backwards. Someone sees a photograph, picks the place, and then finds out the season is wrong, the budget does not reach and the thing they wanted takes four days to get to.
The order that works is: when, then how long, then how much, then where.
When
For almost everybody the dates are the immovable constraint — leave, school holidays, a gap between jobs. Fix them first, then ask what is genuinely good in those weeks.
That is a much shorter list than it feels like, and it eliminates most of the ways a trip disappoints. Patagonia is closed for half the year. Southeast Asia and Indonesia have opposite dry seasons. The tropical Andes and Patagonia are opposite within one continent. The Serengeti’s herds are somewhere different every month.
The seasons page sets out what is good when.
How long
The number of days determines how far you can usefully go, and the arithmetic is unforgiving. Subtract two days for travel at either end, then plan for two-thirds of what remains.
A week is one country, one region, and somewhere under about eight hours’ flying. Two weeks is one country properly or two adjacent ones. A month opens long-haul multi-country routes. Three months or more and the limit becomes money and visas rather than time.
How much
Budget by region rather than by day — costs vary by a factor of five — and separate the fixed costs from the daily ones. Flights, insurance, visas, vaccinations, equipment and the one or two set-piece experiences are frequently a third of the total before you have slept anywhere.
Add 15 to 20 per cent contingency. A trip without it ends early. The budgeting guide has the detail.
Where
Only now, and by working from what you actually enjoyed on the last three trips you took rather than from photographs. Choosing a destination covers the method.
What to book in advance, and what not to
Book: the first two nights, insurance, and anything genuinely capped — Inca Trail permits, Torres del Paine beds a year out, gorilla permits, Galápagos cruises, Japanese accommodation in blossom season, and anywhere in a festival week.
Do not book: the rest of it. Accommodation across most of the world is cheaper and easier arranged a day or two out, and a chain of reservations is the most common reason people leave places they were enjoying.
The rest of the essentials
Visas and borders · Money · Health · Safety · Getting around · When to go · Travelling responsibly