last minute tips for tomorrows shoots

[Oz_Beachside]

hello,

tomorrow I have two shoots and have not had the time to prepare, and would love some tips, so fire away, I'd love to hear your ideas/support...

Shoot 1: Studio flash, white backdrop, model-1 (olive complexion), street casual and swinwear, fashion shoot. (for learning only, so the brief is up to me). Flash will be 2x500ws with diffusers.

Shoot 2: Golden Hour, beachside locaiton, with model-2 and black car. Learned a lot about reflections in a prevous shoot, but looking for tips on getting the lighting / exposure to the model. This time, my challenge will be balancing exposure in black paint reflections, and model-2's skin tones. She is an attractive girl, so I assume skin tones take priority. Fill flash, SB600, tips? Reflector usage?

Thanks in Advance
Oz