No. Currently there is very little consensus on proper practice, and "pick your example individuals randomly", "alternate genders", or "avoid gendered language despite the often stilted results" all have backers.
There really is no good neuter third-person pronoun in English; "they" is abused for the purpose but is still incorrect by many for that purpose. Switching entirely to plural is not always acceptable as an alternative, depending on what the writer is trying to say. Continuously using formulations like "the writer" also produces awkward formulations in many cases.
One can always use first or second person, but many style guides go ballistic when one does so. One can refer to "one", but that gets old fast.
So... Do the best you can, don't stress about it, don't stress about what others are doing unless you really think they're doing it maliciously.