Each step removes one thing you can hide behind - company, then a return ticket, then your own bed, then a short itinerary, then a familiar language. The order works because the obstacle is rarely the destination; it is the unplanned hour, and every stage gives you one more of those hours to practice on.
Step 1: Practice being alone in public
Start here because the stakes are zero: no transit, no booking, no luggage, and you can pay and walk home in ten minutes. Choose a weekday lunch rather than a Friday dinner. Sit at a counter or a two-top facing the room instead of a corner booth, and order a full meal with a drink you have to wait for. The waiting is the exercise. Keep the phone in your bag for the first ten minutes and notice that nobody is watching; servers seat solo diners every shift. The usual failure is treating it as a challenge to survive rather than a meal to enjoy, so you eat fast, skip dessert, and leave convinced that eating alone is unpleasant. By step 2, lunch in a strange town will already feel routine.
Step 2: Test a full day of your own company
Now add distance and a timetable. Pick a town 60 to 90 minutes away by train or bus, close enough that a return is always possible, far enough that you cannot casually go home. Arrive by mid-morning so you get a full day rather than an afternoon. Book exactly one thing in advance - a museum ticket, a trailhead, a lunch table - and leave everything else unplanned. That single anchor stops you from spending three hours in a cafe deciding what to do. Where people go wrong is over-scheduling it like a group trip, with a list of six stops they would not manage with friends either. Lunch alone is not the hard part now; step 1 handled that. The real work is the hour around 3pm, when the anchor is finished and the day is not.
Step 3: Sleep somewhere that isn't home
Sleeping away from home is the actual threshold, since a day trip always lets you retreat by dinner. Book one night in a hotel or rental inside your own city, 20 to 40 minutes from your flat, on an ordinary weeknight. The hard part is not the location, it is 9pm in a room with nothing scheduled. Prepare for that hour specifically: a downloaded film, a long bath, a walk to a named viewpoint. Most people skip the step by booking a treat night so packed with spa slots and dinner reservations that they never sit in the quiet room they paid for, then conclude they are fine alone when they were simply busy. Notice whether the silence feels restful or restless. That answer shapes step 4.
Step 4: Add distance and two more nights
Two nights creates a middle day with no arrival and no departure, and that unstructured day is the whole test. Choose a destination three to five hours away by train, far enough that leaving early costs you something. Keep day one loose and arrival-focused, anchor day two around one long activity such as a hike or a large museum, and leave day three deliberately empty. Packing the schedule so the quiet middle never happens is the standard slip: you come home saying solo travel is easy without having done the hard version. This is also where you learn your tolerance for a bad meal, a wrong turn, and an evening with nobody to debrief - information step 5 depends on.
Step 5: A week alone in another country
Length changes the problem more than distance does. By day four the novelty is gone and you are simply living somewhere alone, which was the goal all along. Book only the first two nights of lodging, then leave the rest open so you can stay longer where you like it. Pick a city with working transit and a language you can at least greet people in, and load an offline map plus a data plan before you fly. Use what step 4 taught you about how much itinerary you genuinely need. One trap is changing cities every night, so you are never anywhere long enough to feel alone, which quietly defeats the point. Another is over-packing, because a week of luggage gets heavy by day five.
A reminder on your phone gets swiped away and leaves no trace; a paper strip taped to a mirror visibly gets shorter as each line is cut off, and it stays there until the last one is gone. Print the five lines, tape them where you will see them before you book anything, and cut from the top. The order matters more than the destinations.