First, I drew in pencil, then I outlined with a Micron pen in size 03.

 

Here is a photo of the the drawings watercoloured.  I used Finetec gold on the French press and wasn't sure how it would turn out when scanned in, so I drew another one and used a non-metallic colour to paint it in.

I have now vectorized the drawings (and have removed the French press that was originally painted in Finetec gold). I have also decided to keep the parts made of glass in white just in case I would like to use these images on a dark background.

Here is the final surface pattern design!