Do you know, że… ?
Surface modeling has this advantage, that you can mold the shape much easier. This is because, that the surface has no thickness, so it is of less importance. minimum radius of curvature. In many cases, surfaces can do anything at all, and it wouldn't have been possible.
However, even in such modeling, some things can be done easier or about.
Example 1.
Something like a snail, therefore it cannot be done in one step, that you have to select a given edge twice. And according to the principle, że zaznaczając coś drugi raz zostanie odznaczone – nie ma to sensu. Of course you can cheat the system by making sketch lines/edges for guidance with a micro gap in between.
Example 2.
The smooth finish of the slender geometry. It cannot be done well in one step, because the final element should then be a point. All, which is drawn to the point (except sharp shapes) it will not be slender and fluid. Therefore, in the first step(s), we create the main shape, and in a separate we make the tip.
You want to learn surface modelling?
I recommend my handbook, in which I described all the tools in detail. In addition, the position contains a lot of exercises in the surface area, tools for molds and creating visualizations.