When sending your project to audio post, there are some simple practices that help your movie to have much solid and safer soundtrack and here are two basic and not less important ones:
1. 2-pop countdown
This tiny piece of video at your timeline's beginning settle itself as a solid project's sync point because when the number two comes with a 8khz beep which is used to sync the new soundtrack once it comes from audio post. Here's an example.
2. On screen timecode
This one can be very helpful to refer and make sure everything is alright when it matches to ProTools timecode. I found this tutorial here explaining how to add it on Premiere PRO.
