Shall I give a template to the rec-letter writer? Many professors, specifically in China, wants students to provide at least a template (half-written letter). In US, is it similar? I've read an article from Harvard Business Review website saying that it is better to enclose a template. https://hbr.org/2010/04/how-to-ask-for-a-reference-let-1-2 I think HBR is a credible source for US professional practice?

However, I am afraid that this practice would seem really creepy to some most honest professor. For example, I once informally ask a professor if he wants a template. He decisively refuses.

After that experience, I never mentioned about a template in US. However, later, some professors (in US) asked me in a vague way that they want a template. So I am kind of confused. What is the default way? 

Here are my options:


Include the well-written template letter along with my materials (he might be insulted)
Mentioning that I am going to include a "narrative list of accomplishment in third person tense", along with my PS and CV. I would also mention that this is just to save his time and minimize his trouble; it is not to force him to write me in this way. If he does not refuse, then I send him all documents. If he explicitly says that he does not want the "narrative essay in third person tense", I would just have him writing the letter or switch that guy.
Ask the professor directly if he wants a template letter written (he might be insulted but he might just think that I am ignorant)
Asking for a template letter is bad practice, albeit probably not uncommon in some countries.

Generally speaking, I'd avoid volunteering any template, and if the professor asks for one, think carefully whether you really want a letter from them.

When you ask for the recommendation letter, just include your CV, possibly a transcript of your exams, and then ask the professor if they need further information. This may be similar to your point 2, but avoids suggesting a narrative. 

You don't specify your field, but I think the above is sufficiently broadly expected in STEM fields (in my experience, even those who ask for a template, frequently recognize that it's bad practice). Therefore, I definitely disagree with the author of the linked HBR article. 

Points of view similar to mine, if not even stronger, can be found elsewhere on this site. See for example:

This very detailed answer from Pete L. Clark

This comment from JeffE