Figure Out What You Actually Want
Before you spend three hours scrolling through flights to places you've seen on Instagram, ask yourself what you're actually after. A week on a beach doing absolutely nothing is a completely different trip to three weeks backpacking through a country you've never been to. Neither is wrong, but booking the wrong one for what you need right now is how you end up disappointed in a place that didn't deserve it.
Do you want to relax or do you want to be busy? Do you want familiar comfort or do you want to be a bit out of your depth? Are you after food, culture, nature, nightlife, or just a change of scenery? You don't need to overthink this. But being honest about it for five minutes saves you from that thing where you book a city break when what you really needed was a hammock and a book.
Deal With the Boring Stuff First
Budget. How much have you actually got? Not how much you'd like to have, or how much you'll definitely save between now and then. How much is in the account right now, or will realistically be there by the time you go? This narrows things down faster than anything else. Southeast Asia is significantly cheaper than Western Europe. Your currency goes further in some countries than others, and that changes the kind of trip you can have. A week in Vietnam and a week in Norway are not the same conversation.
Time. How long have you got? If it's less than a week, don't book somewhere that takes two days to reach. You'll spend half the trip in transit and come home feeling like you barely arrived. Short trips work best when the destination is close. Save the big bucket-list stuff for when you've got the time to do it properly.
Season. Check what the weather's doing where you want to go, when you want to go. This sounds obvious but people get it wrong constantly. Bali in rainy season, Iceland in November without realising it's dark by 3pm, Southeast Asia in the middle of monsoon. Getting the timing wrong doesn't just ruin the weather. It can waste a lot of money on a trip that doesn't deliver what you expected. On the other hand, travelling in shoulder season (just before or after peak) usually means cheaper flights, cheaper accommodation, and fewer crowds.
Logistics. Check visa requirements before you get excited. Some countries need applications weeks in advance. Some have new electronic travel authorisation systems that didn't exist a year ago. Check whether there are direct flights from where you live, or whether you're looking at two connections and a twelve-hour layover. None of this is a dealbreaker, but it's better to know early than to find out after you've booked.
Think About Who You Are (And Who's Coming)
Who you're travelling with changes the destination. A trip with your mates looks nothing like a trip with your parents or a trip with young kids. The adventure holiday that sounds perfect for a group of friends might be a nightmare with a toddler. The romantic boutique hotel isn't much use if you're travelling in a group of six.
Think about what you actually enjoy doing on holiday, not what you think you should enjoy. If you love hiking, go somewhere with mountains. If you love food, go somewhere the food scene is worth the flight. If you love diving, go to the coast. If you love cities, go to a city. This isn't complicated but people overcomplicate it by trying to tick boxes that aren't theirs.
How to Actually Decide
If you're stuck, write a list of ten places you'd go tomorrow if money and time weren't a factor. Don't filter it, just write what comes to mind. Then cross off anything that doesn't work with your budget, your time, or the season. What's left is your shortlist.
Then check flights. Open Skyscanner or Google Flights, put in your home airport, set the destination to "everywhere," and put in your dates. See what comes up cheap. Sometimes the best trips happen because a flight was forty quid and you thought, why not. If you find a deal to somewhere on your list, that's your answer.
If you're still stuck after all that, just pick one. Seriously. The destination you don't choose will still be there next time. There is no perfect choice, only the trip you take and the one you don't, and nobody ever regrets the one they took. Book it, stop deliberating, and start looking forward to it.