Seeing the Northern Lights flare over Norwegian fjords. Savoring the finest patisseries in Paris. Standing in front of the Pyramids of Giza.

Everyone has a mental list of amazing trips they'd love to take someday. But the trouble with "someday" is that it keeps receding into the future. That's why it's time to start planning your travel bucket list: the list of travel destinations you absolutely have to see before you die. Here's how to make it happen.

1. Write Down All Your Wildest Bucket List Travel Ideas

This is the fun part. Set a timer for 30 minutes and write down every crazy travel idea you can think of. Running with the bulls in Pamplona? Sure. Climbing Kanchenjunga in Nepal? Why not? You may lean toward luxury vacations, world heritage sites, adventure travel or culinary experiences.

Don't feel pressured to choose far-flung destinations. Maybe you want to take a Route 66 road trip with your best girlfriend (in a pink Cadillac, of course) or stand on the greens at the Augusta National Golf Club, watching the Masters. Maybe your travel bucket list is about achieving a goal, such as walking every street in New York City or sleeping on each of Scotland's 162 islands (These are real travelers' accomplishments; see more here.)

Can't come up with anything? Look at these travel writers' bucket lists for inspiration.

2. Pare Down and Prioritize Your List

Now that you have your anything-goes list, it's time to bring it down to earth. Do some research about expected travel expenses, the trip difficulty and the overall experience. After reading recent travelers' reviews, you may find out that Dubai is not the luxury paradise it pretends to be, or that Bora Bora is, in this travel writer's opinion, "boring boring."

Also, be honest with yourself about what you enjoy. You may fantasize about trekking on the Patagonian steppes, but if you can't travel without hot showers and a hairdryer, that trip is not for you. In the end, you should have a list of 10 or so feasible trips on your travel bucket list.

3. Identify Your Bucket List Travel Companions

Bucket list travel isn't just about the destination; it's about who's sharing the experience with you. Maybe you envision visiting Disney World with your granddaughters, or Oktoberfest with your son. Start talking to your ideal bucket list travel companions to see if, and when, they're up for joining you on an adventure. And if you want to strike out alone, there's nothing wrong with that.

4. Work Out a Budget

Remember to include travel insurance in your budget, even if you're a frugal traveler. A comprehensive travel insurance plan can not only protect your travel investment if you have to cancel or interrupt your trip for a covered reason, but can save you from astronomical medical expenses if you get sick or injured while traveling.

5. Set Your Travel Schedule

If you don't schedule your bucket list trips, they're never going to happen. But how do you know which ones to plan first? Some factors to consider:

• Your health. If you're in good shape now, move any adventure travel to the top of the list. If you're planning a knee replacement next year, give yourself time to recover before attempting anything athletic.

• Your obligations. If you work, when can you realistically take off the three weeks you need for your Mediterranean cruise? If you're retired, consider traveling off season to save money.

• Costs and currency. If the pound stands at record highs against the dollar, now's not the best time for your London pub tour. Be aware that some cities are unexpectedly expensive, such as Oslo and Sydney, and may break your travel budget.¹

• Threats. A destination on your travel bucket list may be threatened by political unrest, epidemics or environmental pressures — and if it is, you'll have to decide if you want to hurry up and travel there or wait and see. Sign up for the State Department's STEP program and review the latest travel alerts to stay informed.

• Popularity. If one of your destinations was just named one of next year's travel must-sees, you may want to wait until the crowds have cleared. Some perennially popular events require reservations made years in advance. For the Masters tournament, for instance, tickets are sold by random lottery and typically sell out right away.² But don't lose heart if one of your bucket list destinations is difficult to get to. Once you make it there, you'll appreciate the experience even more.