Quick post on this. I'm a Python developer and I suck big time at CSS. So, to avoid too many hair-pulling I still use Bootstrap for "designing" (if you can call that design) my screens.
One thing that I find very disrupting are those icons Boostrap adds to form inputs when validation fails.
Turns out it's pretty easy to remove them, specially if you, like me, are using SCSS to customize it. Just add the following
And... That's it.