when you're writing a title, how do you know what words to capitalize the first letter?

the important words and not conjunctions or "the" unless it's the first word

I think it really depends on what format you are using APA, MLA, etc.

As a general rule, the first word is ALWAYS capitalized and all of the important words are capitalized...words such as or, of, in, and stay lower-cased.

The first word and all the other words after it besides the, on, and, and other commonly used words. For example:

"The City Charlotte is on the Map!"

When it comes to capitalizing the first letter of words in a title, there are different capitalization styles depending on the specific title format or style guide you are following. Here are a few common guidelines:

1. Capitalize the First and Last Word: Regardless of the title format, it is generally accepted to capitalize the first and last words of a title. For example, in the title "The Art of Writing," both "The" and "Writing" are capitalized.

2. Capitalize Important Words: In most title styles, important words such as nouns, pronouns, verbs, adjectives, and adverbs are capitalized. Articles, prepositions (if they are not the first or last word), and conjunctions are usually not capitalized unless they are the first or last word of the title. For example, in the title "Harry Potter and the Chamber of Secrets," all nouns (Harry, Potter, Chamber, Secrets) and the verb (and) are capitalized.

3. Follow Style Guides: Depending on the purpose of your writing, you might need to follow a specific style guide like The Chicago Manual of Style or the Associated Press (AP) Stylebook. These guides provide detailed rules on capitalization and formatting for titles in various contexts like academic writing, journalism, or publishing.

It's important to note that different publication platforms or contexts may have their own rules for title capitalization. Always be sure to check the specific requirements or style guide for the intended platform or context you are writing for. Additionally, you can find various online title capitalization tools that automatically capitalize words based on different title styles.