- High tea/picnic - you could have a cake decorating competition, and finish with a DVD - Quiz à la pub round style - guess the lyrics, etc. - Messy games, i.e. spaghetti makeovers, avocado face packs, twister with paint, trivia cream pies to the face if you get it wrong (did this for my DS2 when he was 12, they're still talking about it!) - If they are a crafty bunch, I once taught a Brownie unit to make flower headbands which are easy and cheap
Go to primary and buy cheap pj's, slipper socks and hair accessories. Have them in the evening. Let them all snuggle under duvets and eat popcorn while watching a movie. Have a quiz (especially picture or guess the song or celebrity gossip based quiz)
DD's 11th birthday one of the things they seemed to enjoy most was making their own pizzas for tea. I made bases in advance & put out loads of toppings for them to choose from. (Also had the advantage of dealing with the fussy eaters!)
We have successfully done tie-dyed t-shirts. Have two buckets or pans with two different colour options, show them one you did earlier to give an idea of techniques they could use, dip and dye them and hang them out. Food afterwards, game or quiz or two. They can take them home or they can be given out the next day or so when they are dry. It is a nice memento, and useful!
They also like a forfeits version of pass the parcel. Instead of layers, when the music stops, they have to take and do a forfeit from the box. Things like: "pretend to be a boy" or "run outside and shout I'm an idiot". If you get good forfeits (google them), they find it hysterical.
And the chocolate eating game. You roll a Dice, put on gloves, hat and scarf and eat a bar of chocolate with a knife and fork until the next person rolls a six.
Chocolate roulette also goes down very well. That should start coming into the shops soon, ready for Christmas.
Or a good old pamper party. Try the cosmetic fairy for good / cheap nail polishes etc that you can put into party bags.