Do you "create" a hypothesis?

Formulate can be used in this context.

Express (an idea) in a concise or systematic way: the argument is sufficiently clear that it can be formulated mathematically

Formulating hypotesis I add this link just for referene.

Ngram

One suitable word is postulate

hypothesis
A supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation [ODO]

postulate
Suggest or assume the existence, fact, or truth of (something) as a basis for reasoning, discussion, or belief [ODO]

Postulate is to suggest a fact as a basis for reasoning or discussion; a hypothesis is a suggestion made as a starting point for further examination. The terms converge.

Some alternatives culled from Google:

developed, proposed, formulated, advanced, put forward, introduced

Google Ngram suggests "advanced" has been the most common of these until the last 30 years when "put forward" overtook it.

In addition to what others have mentioned, you can hypothesize a hypothesis.

put (something) forward as a hypothesis.

Here's a sample Ngram comparing with other answers. Note that Google Ngram does not cull from scholarly articles, so it might not capture academic norms and preferences, which likely vary by discipline, too.

Consider "form."

Lenneberg formed the critical period hypothesis.

A "lipid hypothesis was formed" to explain the rapid increase of heart disease.