The masculine as generic: the specific case of he
Although the singular and non-gendered pronoun they was used quite readily in the literature across centuries, it met fierce criticism by 19th century prescriptive grammarians, who decided to instead impose the sex-indefinite he. Theses androcentric grammarians saw the masculine form as the worthier one. Other languages, such as French in the 17th century, underwent very similar changes, consequently asserting the masculine power, both in language and society. In French, for example, the disappearance of certain occupational feminine forms (e.g., une médecine [a doctorfemale]) was in fact intended as a signal to women that these occupations were only for men.
The difficulty of considering the pronoun he as a generic form has been well documented in the scientific literature, and should therefore always be avoided.
Re-introducing the singular use of they – which only relatively recently disappear – would of course require ignoring grammatical proscription (and you may decide that this will be your case), yet it has been shown that its use is at least cognitively very easy. Although the singular use of they is becoming increasingly popular (again), other alternatives may speak to those wishing to follow grammatical proscription yet avoid the use of he as generic.
We now turn to concrete examples, which of course will depend on the context at hand:
1. Prefer the plural form to the singular one
To: A student needs to consult his notes before the lecture.
Prefer: Students need to consult their notes before the lecture.
2. Directly address readers or listeners
To: If a student wants to enrol, he needs to click here.
Prefer: If you want to enrol, click here or if you are a student and want to enrol, click here.
3. Remove the pronoun
To: Each student chooses the modules he wants to follow.
Prefer: Each student chooses the modules to follow.
4. Use pair forms to refer to both genders, or the singular they
To: When a researcher decides to send a manuscript, he has to carefully check for spelling mistakes.
Prefer: When a researcher decides to send a manuscript, she or he has to carefully check for spelling mistakes or When a researcher decides to send a manuscript, they have to carefully check for spelling mistakes.
We do recommend the order she or/and he for reasons explained here.
5. Reformulate to avoid using gendered pronouns (often using the passive form)
To: The professor who gets published frequently will have a better chance when he goes before the tenure board.
Prefer: The professor who gets published frequently will have a better chance when faculty tenure is granted.
Following the same rationale as for the pronoun he, man or men should never be used as generics. Typically, man should be replaced by terms such as person, people, individual, human, or human being. Note that some research seems to indicate the term human activates similar representations to man (and different ones to woman), and therefore should be used with parsimony.