Is it really cheaper to book on a Tuesday?

That is largely a myth. It is cheaper to *fly* on a Tuesday, but the day you book does not impact the price as much as booking well in advance.

Should I use a VPN to find cheaper flights?

It is rarely effective. Airline pricing algorithms are more focused on demand and route popularity than your IP address location.

How to Book Cheap Flights to Europe

Book your tickets 3 to 6 months in advance and fly into major hubs like London, Paris, or Frankfurt to secure the lowest base fare. Use flight aggregators to compare budget carriers against major airlines, and always use an Incognito browser window to avoid dynamic price increases based on your search history.

Set up price alerts. Use tools like Google Flights or Skyscanner to track specific routes. Set alerts for your preferred travel dates and a secondary alert for 'flexible' dates to see if moving your trip by 48 hours saves you more than $100.
Fly into 'Gateway' cities. Don't try to fly directly into smaller regional airports. Book a flight to a major hub like London (LHR/LGW), Paris (CDG), or Amsterdam (AMS), then use a separate budget airline ticket (like EasyJet or Ryanair) for the final leg.
Use the 'Two-Ticket' strategy. Check the price of a round-trip ticket versus two one-way tickets on different airlines. Sometimes flying into one city and out of another—known as an 'open-jaw' ticket—is cheaper than a traditional round-trip.
Adjust your departure day. Avoid flying on Fridays and Sundays. Research shows that Tuesday and Wednesday departures consistently yield fares that are 10-15% lower on transatlantic routes.

Is it really cheaper to book on a Tuesday?: That is largely a myth. It is cheaper to *fly* on a Tuesday, but the day you book does not impact the price as much as booking well in advance.
Should I use a VPN to find cheaper flights?: It is rarely effective. Airline pricing algorithms are more focused on demand and route popularity than your IP address location.