I made cupcakes and got these edible stickers off eBay that said Happy 1st Birthday. The whole theme was 1st birthday with all the plates, cups & napkins that matched and had no. 1 on it - again I think I got them from eBay. The cake was a double layer of sponge cut out in a 1 with white butter cream and smarties all down the sides. I'd maybe have a few things out for the older kids and you could possibly do games for them, but I think the focus should be on the really little people. So I guess having toys/ equipment out for them and the adults will help them to interact.

We had two parties for DS - in different States with family & close friends and then play group. The mistake I made for both was spending too much time on the food. U went to lots of effort (for the adults) and it was just wasted.

Good luck.