I really don't think there is a set way or rule for how to write a chord progression, if you a re getting the result you want then you're doing it right.

However, a couple of things that you can keep in mind.

If you start with a theoretical approach, for instance, if you start with a chord and then use your diatonic (same key or scale) chord options, you're not even scratching the surface of all options there are.
This is a great way of figuring out keys and progressions and once you get in to chord substitutions and modes it get's really fun and interesting...BUT beware of it sounding stale and boring, you don't want your progression to end up sounding like a mathematical formula. NOT saying it will…but it can.

Another approach is to start from a listening point of view with a purpose and a goal for your progression.
What is the progression for? How should it sound? Is it for a guitar solo? Supporting a vocal? Scoring the next Tarantino movie?

Start with a sound you like and then try all different combinations of chords (you'd be surprised at how cool the "wrong" chord can sound if put in the right spot)
If you end up finding something you love (or hate) you can always figure out the theory behind it afterwards and maybe you'll figure out what it is that creates your own sound or style.

Just listen for what you're hearing and try to play it, rather than trying every theoretical possibility you know…
Music is meant to be listened to, not dissected.

Countless of genres are based on "rulebreaking".
Blues mixes major and minor tonalities, the flat 5 note etc.
Some grunge and pop music in the early 90's started replacing diatonic minor chords with major and suss chords…the list is never ending.
But one important thing about these genres and it's writers is that they weren't written with the specific intention of writing chord progressions that sounded different, they were simply expressing themselves and that's what came out.

Try every different way you can and experiment with what works for you. And also remember that the chord progression does not have to be complicated at all.
It simply needs to just serve your purpose.

Start with listening when you're writing, that's what your audience will do.