Go with whatever you’re finding the most success with, but both approaches are totally valid. It probably depends on your confidence level, and how difficult the pose is. Also, some prefer to start with straighter enveloping lines (similar to the Bargue Method), while others go right in to flowing S curves.
Others will give equal importance to establishing correct proportions in that gesture pausing to check with plum lines or other forms of relative measurement.
But, there are some interesting differences and overlaps I’ve noticed: I suppose you could use the mnemonic GCAT to remember this. Looking at the various popular approaches to tackling figure drawing, it seems they almost always have some form of gesture, construction, anatomy, tone. Update: Since originally writing this article, another resource has been generously shared by NMA on Making Marks (with exercises) with Iliya Mirochnik available to watch for free. Ramon Hurtado’s brand new series on Structural Head Drawing