The bounce or fill-in light is very essential in every shoot. However, if you are not up to buying a professional bounce card, here are some tips of making your own, cheap but very effective bounce cards:

(1) Wrap a cardboard with aluminum foil or any shiny silver/bronze art paper
(2) Use a mirror
(3) Use a white styrofoam - this only creates a very light sheen compared to silver, metallic objects

Here is a sample of how I used my old beauty mirror which has an adjustable neck for my alcohol shoot - it was extremely useful since I didn't have an assistant to adjust my bounce card:

I shot outside my terrace but the mirror gave an obvious circle reflection on the bottles. Lesson learnt! Can you tell where the reflector is on the Bombay Sapphire? It is between the letters A and Y on 'Bombay'...

NOTE TO SELF: need to make a cleaner shot next time! I'm not satisfied with how the blue liquid came out.