I usually recommend beginning the session with some traditional postures then adding more interactions with your child (ie. kissing, hugging, throwing in the air - real intimate, lifestyle moments).
I take pictures with the following combination father&child, mother&child, mom&dad, sister&brothers but I am open to your suggestions.
This session can be followed by other family celebrations such as birthdays, kindergarten graduation, first school day, Santa's day, etc. which will complete the family album. The latter can then be offered to grandparents or close family members.