(Karen and Bradley's talk about using proprietary software is a starting point for this.)
I repeatedly go through phases where I think I'm just on the cusp of sitting down and writing a definitive apologia for my approach to using free software and, in particular, how that approach handles the interface with proprietary software and, most importantly, its users.
As with so many things I sit down to write, though, I find that there's something I have to write first. Before I can describe what I try to do, I realize I need to look at the broader picture. The upshot of this is that if I wait until I can do everything I want to do at once, I'll wait forever. This is where I need to give myself permission to do an imperfect, incomplete job on the way towards building something bigger. One step at a time, one bite at a time, as it were.
An effective, sustainable approach to promoting free software and minimizing the deleterious effects of proprietary software acknowledges that this is a long road, an endurance race, not a sprint. It's a long term project and making sure we remain healthy as we go means recognizing and acknowledging our own struggles with proprietary software. This allows us to perform some self-care while providing a good grounding from which to extend empathy to other people using proprietary software.
Because this is a long-term project, because the forces that militate towards the production, promotion, and use of proprietary software are endemically vast, the project of eliminating proprietary software is ... monumental, epic, a task of such scale as to seem insurmountable.
We need guideposts along the way to mark our path and milestones to measure our progress, individually and collectively. We might lose our way from time to time, which is fine. When we do, though, we don't want to get stuck in a big production about where we're going and how to get there. Orienting ourselves to these guideposts allows us better to keep our focus on those around us with whom we live and work. This helps keep the feedback loops operating on a healthy and humane scale so that we can continue to care for each other and help each other along the way.