Here are the most common rules for capitalization in titles:
* Capitalize the first and last words.
* Capitalize all nouns, pronouns, verbs, adjectives, and adverbs.
* Lowercase articles (a, an, the), conjunctions (and, but, or), and prepositions (of, to, from) unless they are the first or last word in the title.
* Lowercase short prepositions (of, to, from, for) even if they are more than four letters long.
For example, the title "How To Train Your Dragon" follows these rules:
* How - Capitalized because it's the first word.
* To - Lowercased because it's a short preposition.
* Train - Capitalized because it's a verb.
* Your - Capitalized because it's a pronoun.
* Dragon - Capitalized because it's the last word.
There are some exceptions to these rules, and different styles may have slightly different preferences.
Ultimately, the way I capitalize words in a title is based on the specific style guidelines I'm programmed to follow.