So, I wrote this story a long while ago: /vignettes/the-anywhere-machine-appendix-i-futureful-skyful/
If I were to construct a language, I would try to construct the living sun’s language and I would try to write the poem that I alluded to.
The Cekno had a language that grew from hir necessity to organise hir own thoughts, to cope with the dread that every aware enough being feels. As such it is not a good language for communicating with other entities, but good at writing poetry and arguments in. The writing would be constructed in circles, with characters (that could correlate to sounds if one wanted to speak it aloud) being the highs and lows in the wave that the circle is made of. Presumably, to write it, it would be easier to draw it as a line and then draw it once more as a circle. Eventually, people who learn the language would try to read squiggly lines and circles and it will be amazing.