Maybe a stupid question but does anybody know if it is okay to fly with Aer Lingus & return with Ryanair? Booking flights to Prague & times suit me best if I could do this. Thanks.
Yep buy to single tickets. Its like getting a bus from Dublin to Galway (single ticket)and getting the train back (another single ticket) both are independant of one and other. Probably not the cheapest option though.
Of course it is fine to do that. With traditional airlines, there usually is a return price that's better than two single journeys. Not so with budget airlines. You can book an outbound flight with one and a return with the other, no problems.
Remember though that if you book luggage, Aer Lingus allow 20kg and Ryanair only 15kg.