Simple tip: Set scene to only one frame
This 'tip' is probably obvious to most, but since I just figured it out, maybe it will help others. I have a tendency to get the timeline set to something other than frame 1, then have to go back and move and delete keyframes when I actually meant to not animate anything, today a lightbulb finally went off and I just set the scene to 1 frame only, tada, now until I actually need to animate something, I won't have that issue again.
Had this issue the other day. Suddenly had frames and different "updates" to the figure in each (pose, hair, progress on fit). Realized I had gone into some sort of animation mode and had been advancing the frames. At that point, I went online and did a crash course on animation controls, deleting frames, using the graph feature, etc.
Now I do basic figures and scene sets in "1" frame mode and save them as a base file. Since I use the same characters in different modes (designing a book cover or a book promo animation) I save them as Nude with hair.
When I need to, I open them , manipulate (clothes, props, poses,etc) the figure and save that as "Character XXXX for Cover YYYY". Sure, it takes up more space, but I can't screw up the baselines that way. I also don;t do anymore "physical feature" changes in those versions, except for things like poke thru's, etc. BUT...the base figure stays nice and safe in another file.
I then import those modified files into the animated scenes or the final cover to be manipulated. There may be an easier way, but this is the safe way for me.
I run into this problem all the time, and it never dawned on me to do what you suggest. Sometimes the best answers are hidden in plain sight - many thanks. :)