Final answer:
The best way to declare a section with an h2 heading and use a detail tag is to neatly organize the HTML code, using h2 for the heading and enclose the collapsible content in detail and summary tags.
Step-by-step explanation:
The proper way to declare a section with an h2 heading and utilize the detail tag is to structure your HTML code so that the section is clearly defined, and the details are enclosed within the detail and summary tags. An example of this would look like the following:
More about me
My Childhood
Stuff happened, I grew up, I learned many new words, such as mother, father, sister, and teacher, which made the world blossom for me with happiness.
This structure provides a neat and organized way to present a collapsible section on a webpage, where users can click on the summary to reveal more information.