My 9-year old daughter had her first sleepover last January. It was a wintertime theme.  We made snowflakes out of plain white paper and made them into invitations. Very cheap and a fun activity for all ages.  The day of the party we decorated with more snowflakes and snowmen I had in my Christmas decorations. When the girls arrived they made as many words as they could out of the word "snowflake".  This keep them occupied until everyone was there and I could greet parents. Then we played wrap the snowman. Played the same way as wrap the mummy but we changed the name. Two teams wrap one player up with toilet paper until nothing is showing.  Then we played pass the snowball (a Styrofoam ball), played the same way as hot potato.  The player with the snowball when the music stops is out. Don't forget the freeze dance. Then we decorated knit gloves with beads, glitter and rings. I found the gloves for $.75 a pair. Something different the girls really enjoyed.  Not to mention practical in January. The food was pizza, drinks, munchies and a sundae bar. The girls loved the many topping they had to choose from for their ice cream. When we finally ran out of games we got out the sleeping bags and watched what else Frosty the Snowman. A good choice for this year would be Snowday. The next morning each girl left with a loot bag filled with candy, pencils, erasers and stickers with snowflakes on them.