To feel right or natural; to fit well together or suit someone/something; to sit well with someone. Commonly used in conversational Japanese.
このジャケットはデザインも色も私にしっくり来る。
This jacket's design and color both suit me perfectly.
家具の配置を変えたら部屋の雰囲気がしっくり来た。
After rearranging the furniture the room's atmosphere felt right.
その言い回しは文章にしっくり来ないので、別の表現に直そう。
That phrasing doesn't sit well in the text, so let's change it to another expression.
あの人とは話していてしっくり来るから、気が合うのかもしれない。
I feel at ease talking with that person; we might get along well.