How do I discover the best birthday party themes for adults?

Here are some of the best birthday party themes for adults:

Cocktail Party

Masquerade Ball

Hollywood/Glamour

Decades/Retro

Beach/Luau

Garden/Outdoor

Karaoke/Game Night

Mystery/Murder Mystery

Casino/Gambling

Sports/Athletic

Boho/Festival

Travel/Destination

Cooking/Foodie.