How do I know when you are on cue ?

Question:
How do you catch a 1st or 4th beat messure to insure your on cue , and what should a proper Mix sound Like ....

Choices:
You should be mixing from the 1st or 4th beat Messure on most songs , (House , Trance , Techno , Dance and Tribal most offten yous a 4-16 beat messure , The first is easyest to catch.when there is Vocal in the song . The 1st beat is always at the start o
When you mix your song in make sure your bass on the cue side is lower then the track your Mixing into . (Reason