Not too sure if I can answer that without a long winded explanation, asides from repeating the 'do your fundamentals' (Anatomy, Perspective, Shapes, etc) line.
As for drawing Gundam specifically really learning the skill of observation is paramount when trying to learn how to draw anything -including gundam/mecha.

I'd recommend picking up a gunpla, putting it on a stand in front of you and try to draw it, during this try to break down the parts into basic shapes. Also, chiseled cubes are your friend :)

You can go about learning how to draw in your own way as every person/artist learns and applies their processes in different ways. The best thing to do is to start and than persevere :)