<human>:  What are the best budget-friendly ways to travel in Europe?
<bot>: Some of the best budget-friendly ways to travel in Europe include taking advantage of low-cost airline carriers, such as Ryanair and EasyJet, utilizing ride-sharing services, such as BlaBlaCar, taking the bus via Flixbus, taking advantage of Eurail passes, and staying in hostels or couchsurfing instead of hotels.