Christening Outdoor Party

Hello, It is not exactly a birthday party, but a reception after the christening (we are Christian Greek Orthodox and the christening is not the same as in Catholics, let`s say it is a very big celebration) of our baby girl that will take place to our garden. I want to make the decoration myself and the invitations. Any ideas? We will name her Anna, and she is 3 months old. I am more interested in ideas of how to decorate the trees, what luminates to use, What kind of centrepiece. I have decided about the favors, and i am thinking that the colours should be pink, white and lime. I would prefer if I didn`t use real flowers at all.