GMRS

I have a total newbie question...

I understand that a family can share one GMRS license. I've also read that GMRS stations must identify themselves. How does this work in practice? It seems impractical to have a conversation between family like, "WXX123 son this is WXX123 dad, are you ready to meet up for lunch?" If my family were to use a CTCSS or DCS code on a given frequency so we're only hearing each other then could we ignore the call sign formality and chat freely?

I ask because I'm exploring the idea of using GMRS radios while skiing. My family has used FRS radios and they're usually okay, but when we get spread out across the mountain there are times we could use the extra transmit power.