Unfortunately I had to have a bit of a breakdown/ crisis to achieve this separation (not recommended!). I was away from work for 3 months and everything carried on without me, just fine! Of course things were done differently, perhaps not quite as well as I would have done them, but the wheels carried on turning and no-one died. This was a useful realisation for me.
I think I was also going about it the wrong way - I thought I would be perceived as more successful and committed if I was always visible in the office, always answering emails promptly out of hours, always doing things straight away. I was caught up in trying to prove to someone (no idea who) how efficient I was.
But I looked around and realised no-one else in my immediate team was doing the same. And no-one thought they were failures, or inefficient, or not worth the salary....so I realised it was me being a bit of a mug really.
This was about ten years ago. Since then I have completed a couple of major professional achievements- just slower than I wanted to. I think I was trying to rush progression too much.
So, for me it took a shift in mindset more than anything. But, what has helped since then is agreement with colleagues in my immediate team about email replies in ‘working’ hours, so we all try to make sure that we don’t send or reply at 5am/ 10pm, as this creates expectations that this kind of extended working is the norm, and that actually does a dis-service to colleagues working normal 9-5 hours, it’s not fair on them.
I also use out of office replies more, perhaps if I’m working on something big that needs a day’s concentration e.g. I am away from my desk most of the day on Friday 13th blah blah. I’ll get back to you etc. No one has had an issue with this.
I also say No more often. Perhaps I would be interested in doing xyz or going to an event, or training, but if it’s not essential or going to be really valuable to me, it’s a No.
I also over-estimate how long tasks will take me and allow myself more time. Yes, I probably could write that report within 3 days, but I’m going to tell you it’ll take a week, or perhaps ask for more time on an unreasonable deadline. Less pressure on me, and no-one seems to mind.
So I began to care less, and I can detach from work much more than I used to, because I know my health is at risk otherwise.
Sorry that’s not really many practical things to do, but that’s how I’ve experienced the transition from work absorption to separation. I really hope you can work towards this too!