The two-second rule for empty states
An empty state is the first thing a new user sees and the last thing anyone designs. Give it one job: tell them what goes here and how to put the first one in. Everything else is decoration.
Stop centering your forms
A centered form makes the eye hunt for the next field. Left-align the labels and inputs, keep the column narrow, and the whole thing reads like a sentence instead of a puzzle.
Loading is a feeling, not a spinner
People forgive slow; they don't forgive uncertain. A skeleton that matches the real layout feels twice as fast as a spinner that tells them nothing.