Hi cp
I can give you my experiences and what i've been told on this subject. In recent times i've come up through the lower levels in International Ballroom.
At the lower levels (beginner, novice, to some extent intermediate)judges look for good basic technique - immaculate footwork, good leg work, posture, poise, balance, timing, good linkage with your partner. Essentially, you need to demonstrate you have the fundamentals right.
Good timing is essential. I have a friend who has a problem with timing and rhythm. He and his partner look great on the floor excpet he keeps losing his timing, and he's penalised heavily.
Picture lines and musicality: - picture lines aren't expected at the lower levels. Make sure the syllabus includes them. In europe, the restricted syllabus for beginner and novice precludes any 'fancy' steps. Even a double back lock or a travelling check in a slow waltz is banned! Clearly musicality is going to help you and make your dancing more attractive.
I once won an intermediate event dancing beginner steps (for waltz and quickstep) very well, against others doing oversways and checks. It taught me something.
Of course, in your social dancing, you can just enjoy yourself, and if you can dance more advanced material well, you can look forward to great things higher up the ladder.