I'm not entirely sure if this is the kind of thing you are talking about but I find something about sweaters / cardigans / sweater vests seem to lend themselves to a more cute look. To an extent I think so do things that might be considered nerdy like button up shirts / glasses / suspenders. Also colors that are usually considered more feminine but styled in a masculine way like pinks and purples.
One of the reasons I prefer the colder months. It's so much easier for me to look nice in warm clothes. Layers tend to be eye catching, and it's nearly impossible to layer up in the summer months here without nearly expiring from heat exhaustion.
For summer months I think Hawaiian shirts or other patterned shirts are cute. You can pair them with khaki, navy, or jean shorts for a cute look that is still cool.
Funny you should mention those. I actually purchased my first one not too long ago! I've never been a fan of floral patterns, but the retro/neon revival has helped with that somewhat.
My partner also doesn't like floral prints but recently bought some other "summer patterns" like fish and a pink/purple plaid. There are other options out there.
Hmm, I'm not too into the sweater look personally, but I see what you mean! The sweater vest in particular reminded me that a good vest (sweater or otherwise) can be a versatile option for falling somewhere on the range of cute and/or sexy.