"The Empire? Too mainstream."
Han Solo: Wear an off-white long sleeved collared shirt, black vest, thick black framed glasses, style your hair and wear an optional beanie. + Rebel alliance logo coffee cup which we just used a blank paper cup and sharpie-d the logo. (not pictured: Wearing just normal blue jeans & black shoes. anything stylish works!)
Princess Leia: Wearing an oversized off-the shoulder t-shirt dress. Hair put up in classic Cinnamon Bun style + thick black framed glasses. (not pictured: Wearing ripped tights & black vans. anything stylish works!)
Toy guns would probably be a plus. Finger guns work just fine :P