Lightweavers and Truthwatchers must have some thing about it or the surge of illumination that there are to feel when an unmade is active. There are the only 2 of the radiance that knew something was off about the tower.
To Shallan: Don't marry Adolin, the ghostbloods will use you more.
Don't join a cult
To Dalinar: Stop trusting one of the most untrusting person each book.
To Jasnah: Don't kill members of secret of society.