Suffering From Zoom

I tried to make a fashion illustration but one of the main problems with using digital media is not being able to consistently see the full silhouette when zooming in and out. Sure it helps when I can go into a detail and really draw it, but the problem becomes whether or not that detail is in proportion to the rest of the drawing, and definitely with fashion illustration, I need to take into account the entire piece because the proportions are all stretched out. Not happy with this base line drawing but hopefully will sort it out when color is applied. This is my friend Peter's dress design.