Munich → Barcelona

Regional holiday calendars matter more here than the business week does. School holiday blocks and long public-holiday weekends move a large share of this route's passengers at once, and they are known months in advance, which means the seats at the lower fare levels tend to go early. If your travel is fixed inside one of those periods, booking ahead is not a tactic so much as a necessity.

Outside those blocks, the picture is far more relaxed and flexibility pays well. Compare several consecutive departure days on this page rather than pricing a single date, and be willing to trade a convenient departure time for a cheaper one. If you are travelling with family or in a group, remember that you need several seats at the same fare level, so start looking earlier than a solo traveller would.

With fewer options on a route, comparing everything available becomes more important, not less — missing one airline can mean missing the only genuinely low fare on your date. Look at all the carriers together on the same dates, then compare them on what you will actually pay: cabin baggage rules, checked bags and seat fees can reorder a shortlist completely once they are added in.

Give yourself a little runway if you can. Watching this route over several days shows you the range fares normally move within, so you can act quickly when something lands at the bottom of that range instead of second-guessing yourself. Pingsme is free, updates at least daily and keeps everything on one page, so the final check before booking takes a minute at most.