Relying on autoback from Max which is a life saver some times and then using Maya and forgetting Maya is dumb and doesn't have autoback and losing tons of work : /
Best things ive done since Ive got into 3D... Change the space bar key. Change autoback to 40 every 3 minutes. Added a hot key to "select element" in the UV Editor. The mistakes are everything that you cats had already said.
Autoback has always been primary source of my misery. I've worked in archviz company for a while and max would always decide to do a backup of my scene when I was trying to attach 50000 objects together. Which led to crash :) So I developed a habit of turning it off and doing incremental saves myself.
Spacebar in 3dsMax is the worst. I used to just think that max was soft crashed and I would exit and restart the program. My biggest D'oh...I still do to this day. Starting work on a new section of a model that is based off an old section, and accidentally using 'instance' instead of clone....then working with the original…
The ctrl-z spam in max for sure. Working on a 32bit OS with 4gb of ram, not saving after adding a bunch of clips to motion mixer, then mixing down carelessly as if it wouldn't crash. Upgrading to a newer version of max and forgetting to setup/import my keyboard shortcuts then wondering why the "defaults" aren't working...…