Well, since last year I am done with my "habit" of my ex... that took care of a lot of shit :-D.
To be fair, not all of the clutter was his (by far) but we never got to the bottom of stuff. He didn't want to and he didn't want to do his share of housework and family responsibilities, so I was often too tired and did not have the energy to take care of it all.
However, I do think that a lot of my problem is not "habits" but "history", I had a lot of stuff from teenage/early twenties and from what I have inherited from grandparents. I have never had anything like a shopping addiction, more "cannot get rid of sentimental stuff". I am now almost 50, I don't buy a lot of stuff, so there has been more going out than coming in for several years. Also, in the last few years, I have managed to let go of a lot of sentimental things, that didn't really mean that much to me, which meant that my moving and down-sizing last year was pretty smooth.
So yes, I have changed my habits, but my problem was always "keeping", not so much "acquiring".
I am making sure that I am aware how much I have changed and how much my life has changed, and that I try to remember how much stuff I had and how that impacted me.