I speak French, so what I have will not necessarly translated very well.
I create some words, for time to time. That which I most often use is "trexcellent", which is "très" (very) + "excellent". That was because I wanted an absolute superlative to "excellent", which already is a superlative term.
Often, is has a bit of a historical flavour. I like using features of the language which were lost. I had a period of using the superlative suffix "-issime", which is inusited in modern French but for a few cases (unlike other Romance languages): "puissantissime", "grandissime", "mochissime", etc.
I also use many words strictly in their etymological meaning; for example, "extraordinaire" for any thing out of the ordinary, without the usual meliorative connotation (e.g. "Hitler was extraordinary.").
I like to use words or concepts from one field in another. For example, I would use "équestre" (in the Roman historical sense, as in "the equestrian order") more or less as I would use upper middle class. In the same way, I like to use "patrician", but although it is ultimately a Roman term, it is more in relation to the higher class of medieval/early modern cities.
In general, I have periods during which I will use certains words a lot. It comes and goes.
All this is for my own pleasure. I don't use any of this when I need to be understood, only in very informal context or with my family.