As one of the main points to a vfr fp is so they know where to find the wreckage if you don't arrive, I think you can use any identifiable points, provided they start and end somewhere either with an ICAO or ZZZZ with some manuscript notes in remarks.
Not only are waypoints and intersections useful in terms of direction, but some, like ORTAC, which are in all good GPS'
are useful FIR boundary markers. Makes life easy for everyone.