Looks refers to eyesight and visuals, while seems refers to everything. "The sky looks dark. The wind sounds creepy. Today seems like a good day for staying inside."

looks - to describe an observable condition e.g. She looks sad. (from an observable state or behaviour) seems - to describe a perceived condition e.g. she seems sad (the person who makes the statement has a perception about the condition of the subject)

But be aware that native speakers will often use "looks" for something that isn't visual, like "today looks like a good day to (do something)". I don't know if it is one of those mistakes that native speakers make, but you will hear both!