It's actually quite simple for anyone to create a portmanteau, although some care should be taken for anyone wishing to make one that is truly noteworthy or likely to become part of the general lexicon. A portmanteau is created simply by combining two or more words, or morphemes that are part of words, together to create a new word that has meaning connected to the original words. Unlike a contraction, however, these words do not appear immediately together in a sentence otherwise. Simple examples of suitcases include words like "smog" from "smoke" and "fog", or "Internet" and "international" from "network".
A portmanteau, sometimes also called a "mix", is a word that is built by combining two or more words together. Word parts, rather than whole words, can also be used to create suitcases, although these parts are often complete morphemes that make the original identifying words. In some respects, similar to a contraction, an acronym is formed from using words that do not naturally appear together within a sentence. A contraction is formed by combining two words that would appear together, such as "can" and "can't" in "can't"; however suitcases use words like "smoke" and "fog" that would not naturally appear one after another in most sentences.
Almost any type of word can be used to create a portmanteau, although nouns are some of the most commonly used words, and adjectives and adverbs are common in some places. The term "suitcase" was first used to describe this type of word by Lewis Carroll, who uses numerous suitcases in his poem Jabberwocky. Most of these suitcases, however, were created from adjectives and adverbs together, such as "furious" and "fuming" that combine together to create "frumious." Suitcases created from these types of words often end up seeming like meaningless combinations of sounds, while nouns can form more recognizable words.
The simplest way a portmanteau can be created is through the combination of two words or parts of two words. "Internet" and "pollution" are simple examples of these types of suitcases, although other words such as "lunch", from "breakfast" and "eat" and "edutainment", from "education" and "entertainment", are also created to from such simple combinations. Anyone can create this type of portmanteau simply by combining two words or parts of two words together, such as an "ordeal" that causes "boredom" referred to as a "boredeal." These words are often more engaging or memorable if the sounds created resemble the original words.