This can open up some doors to a faster workflow or more advance level of modelling by helping others discover the things you wish you knew sooner and maybe you'll discover something someone else knows or does that may be a game changer for you as well.
Ill start off with these simple ones that took me a long time to figure out.
"MORE CONTROLLED VIEWING ANGLES"
The ORBIT FLYOUT (at the bottom right near the play/pause buttons) can be used to rotate your view a way that alt+mmb will not allow. I've gone through so much frustration not able to get the exact view i want in a project. I could never get oddly angled objects on screen how I want for using something like the "Screen" Reference Coordinate System (lining up two vertices horizontally or vertically for a controlled scale or other transformation in the exact direction or angle you want).
"SMOOTHER MODEL WITHOUT/BEFORE MESHSMOOTH"
I preferred maya because you can press 3 for a smoother model, when modelling in Max I hated constantly having odd folded polygons and triangle shadows after a fair amount of modelling unless I add meshsmooth. I don't know the depth of "Smoothing Groups" in detail but i know a simple tip to make my model look cleaner. First, I drag a selection over all the polygons of my object (or ctrl+A to select all), next go down the Modify Menu til I reach "Polygon Smoothing Groups" and I click "Clear All" (you will lose smoothness for a moment) and then I click the number "1" and all my polygons are in the same smoothing group and looks much better.
Let us know your tips or secrets for 3DS Max Modelling 🙂