The first incarnation was closer to Chinese or ancient Egyptian in that he tried to create a different symbol for each word. Then, after creating over a thousand symbols and still being far from his goal, he went back to the drawing board and took a purely phonetic approach.
Not being literate in English, he simply borrowed sritten symbols he saw, including numerals. Ultimately, the phonetic-based system was a success and spread through the Cherokee nation quickly.
Humans have only invented writing independently two or maybe three times. It's amazing how much easier it becomes just knowing such a thing is possible!
I'm sure many of the readers of this fine forum know the quote (and provenance, which I don't) that is something like 'any sufficiently advanced form of technology is indistinguishable from magic'.
An interesting note is that somewhere in the development of Egyptian writing, the vowels got dropped from the syllable representation, leaving an abjad which the Phoenicians borrowed... and then the Greeks added vowels to obtain the alphabet, while Sanskrit took a different path to get the abugida. As near as we can tell, this one turn away from a syllable-based phonetic system is unique in the history of independent development of writing systems.
 Indus Valley Script is undeciphered, and may not even be a full writing system, and so it is excluded here.
 This did not happen for the Chinese, but the Japanese borrowed the Chinese script and made two syllabaries out of it, hiragana and katakana, following the same basic principle.
 - https://en.wikipedia.org/wiki/Aleph
This is not how Egyptian hieroglyphs worked.
An common example
𓉐𓂋𓂻 - pr (v) - to leave
𓉐 is a house. It represents, here, the sound pr, which is the Egyptian word for house.
𓂋 is a mouth. It represents the r sound. Here, it's being used as a phonetic complement to emphasize that we're spelling a word here and not talking about a house.
𓂻 is a pair of legs. It's being used as a determinative to tell you the word has something to do with walking.
In the categorization of writing systems, alphabets (such as Latin) encode each phoneme as a distinct letter; abjads (such as Arabic) encode only consonants, with vowels as optional diacritics; abugidas (such as Indic scripts) primarily encode consonants but mark vowels in some systematic way; syllabaries just encode each syllable as a unique glyph without any systematic modification; and logographic systems don't have any systematic phonetic component (although they usually are influenced by phonetics, e.g., the rebus principle of diagramming abstract concepts by use of homonyms).
Sequoyah had access to an English-language Bible, so although he couldn't read the Latin text, he used several letters as inspiration for Cherokee, which is why you see Latin characters that correspond to completely different sounds.
OMG. I really feel for the unicode standards guys. The variation in written language is incredible.
Just for fun, boutrophedon <https://en.wikipedia.org/wiki/Boustrophedon#/media/File:Bous..., writing as the ox plows.