It’s not really sewing anymore, but if you wear a lot of knits it might be worth having a “needle for fixing pulled threads”... I don’t actually know what the proper name is in English, in French it’s called a “rentre-fil”. Examples 1 and 2.
It looks like a needle, but without a hole, instead having a “rugged” part that allows you to catch the thread and pull it through the fabric/knit so that it’s not visible anymore and doesn’t get damaged further.

I’m not sure if what I’m writing makes any sense, ha ha.