What should couples consider when buying a mattress?

A bedroom with plaster pink walls and a bed with a cream headboard.

Choosing the right mattress is hard enough for yourself, but what about when you need to factor in someone else’s preferences too?

Couples often cite sleep as one of the most contentious issues in their relationship. So what can be done to make sure you don’t end up in relationship strife when choosing the best mattress for two?