One thing that helps me is either reading about a cool ability or seeing one used on Critical Role. Then I try to build a character around that. For example, the bard in Critical Role used a powerful illusion spell to avoid what would have been a difficult combat encounter. So I designed a bard focused very much on illusion magic and started coming up with related personality features. She always lies and her backstory involves conning this rich old lady for years, but when the old lady dies she feels bad about it because the lady was my character’s only friend. Don’t try to pick an amazing starting point. Pick any starting point that interests you, then start building that out and eventually you will find an interesting conflict for the character.