I usually just turn testing cheats on and send them teleporting to the corner of the world... =3=;;
A good mod to have for this is MC Command Center. It let's you set the maximum sims on a lot, not household but lot. Minimum is 5. So I use a 5+ sims household, that way there won't be random ppl walking by. Also, turn off autonomy, and use testingcheat on and shift click on mailbox I believe, or sim, to disable need decay. Also, take note of the time of day, makes or breaks a shot. Which is also why you wanna turn off needs, so sims don't come randomly wandering into your scene to go to the bathroom while ur waiting lol.
