The feel of Star Wars - a rag tag group with some snarky banter and humor. A behemoth enemy that can't be faced head-on by conventional means (without consequences). Cool locales with aliens and unique environments to deal with. Desperate missions to infiltrate, escape, rescue, sabotage, smuggle things under the nose of the empire/crime boss, etc. There must be occasional vehicle chases, spaceship dogfights. Vehicles and Starships with character - breaking down, getting fixed, held together with space duct tape and hydrospanners. Occasional environmental hazards like asteroids, space worms, sea monsters, and Saarlac pits that guys can fall into/get eaten by. Huge things getting blown up sometimes.

That stuff should be liberally sprinkled throughout most game sessions and adventures, making sure that it is all flavored according to the characters' motivations and goals and situation in a naturally flowing/emerging nature. When in doubt, throw some stormtroopers or pirates in there and have a good old blaster fight to keep things exciting.