Mostly based on my own style, but here are some of examples of what I envision sundaycore looks like (for people with varying moods, many aesthetics, who contain multitudes like me): 

My preference is mostly androgynous and modest, and mostly encompass 3 aesthetics: classic academia, 90s artsy/plant mom, and cool grandmacore. 

- long plain shirts in solid colours or classic neutral tones

- also long checkered/plaid/stripes shirts

- long coats (I’m talking trench, pea, double-breasted, all of them)

- blazers (and and all, bonus if vintage/thrifted)

- pullovers and turtlenecks

- sweaters and vests 

- creams, khakis, browns

- muted colours

- overalls (denim, corduroy, etc)

- loose blouses

- button up shirts

- boatline tops 

- thin stripes on shirts 

- long skirts

- high-waisted jeans

- colourful shirts (geometric shapes)

- mom jeans!!