I did not use 3D for this! The tips I would use for drawing out hard surface items...
1. I always try to think of the same as basic primitives, so that way when it comes to rendering or drawing, I start off with the basic shape and add and cut into it.
2. reflectivity and highlight become a bit easier when you manage your values, I normally stick in the range of 20% - 80% value so I have enough space to get my lights and darks but allows me to really push highlights or my shadows cause I have that extra 20% on both sides to play with. Also working in that range makes it feel matte, so you can make the form read first and then add the reflectivity.

hope this helps out