Discourse Structure - the organisation of the text or the "journey" the text takes. Look out for discourse markers like "firstly" "secondly" "in conclusion" or features like bullet points that are used to create a structure.
Graphology - the visual elements of a text such as layout, font sizes and type, use of images, etc.
Lexis - the specific word choices a writer uses.
Grammar/Syntax - sentence structure, function and length.
Phonology - the sounds of the words. For example onomatopoeia or rhetorical devices like repetition.
Pragmatics - the underlying meaning of the text in context. For example "Oh, that's great!" could be meant literally or it could be said sarcastically and mean the opposite. To fully understand the pragmatic meaning we need the context.