A business philosophy that works for me.
Making yourself redundant is a process of identifying where you are indispensible to the enterprise that you happen to be working for. Don't believe anyone who tells you that no-one is indispensible. That's a strategy that many folks employ to make you feel lucky to have your job. Everyone is indispensible, in their own unique way.
Think of the time you really needed time off, (a mental health day, for example) but went to work out of diligent loyalty for the enterprise and because work needed doing that no-one else could do as well or as efficiently as you. All things being equal, that was a moment when you realised that you were in some way indispensible.
The secret of being able to take time out when you need to, without feeling guilt, is to make yourself redundant.
At every opportunity, whenever you remember, as often as possible, think of ways in which you can hand over at least a small part of your function or duties to another person. Treat this as a meditation, that is, don't beat yourself up for missing opportunities to apply this pro-active technique, but do apply it whenever your mind returns to the thought.
Little by little, you will be building an environment where you are able to step away from your job, with a progressive lessening of the guilt that can spoil well-earned time out.
This little process can especially assist owner-operators of businesses, as many of these people realise after years of building a successful business that they and their business have become so intertwined and interdependent that all value that could be realised in the sale of the business has been leached out because of this unhealthy (and unprofitable) symbiosis.
Do your enterprise and yourself a favour. Make yourself redundant.