You can throw a card party or keep a Bollywood theme part where everyone can dress up as their favourite Bollywood characters. It can be a colour theme party too where you can dress up in one bright festive colour combined with another like red and green or yellow and pink. If you have friends from different states, then you can tell your friends to dress up in their own state costumes. All you need to do is let your imaginations go wild and think of some interesting theme.