There are some essential epistemes for doing a prose. Like it needs to flow, and there's supposed to be at least a topic or something solid in it. But when we are talking about good prose style, there are too much the criteria to be met. In short we can say, for a poetics of proses, one shall always aim to something new and aesthetic. This is partly because that a prose which either provides excitement or satisfaction could be called a good one. So if you don't have a good story, don't do a prose; if you don't have well established rhetoric skills, don't do a prose.