I normally name OCs by associated-word/background/forshadowing keywords and then google "are there any [character gender] names for [keyword]" and pick the most fitting/best sounding option. Either that or taking the letter-switch-cipher I made and making a name out of that.
like I once searched "are there any girl names associated with air and the colour green" and got the name Sage for my OC, and used a similar naming scheme for all the OCs from her group like Ocean (water + blue) Ember (fire + red) Violet (earth + purple) Lumi (light + gold) and Shad (shadow + black).
Or when naming the characters for a different idea I was thinking of I went with Lex (Alexis + Alexander), Lorelei (lore/exposition queen + excessive lier), Vega (star + light = brightest star), and Ruben (a male given name that has its roots in the Hebrew language. The name means “behold, a son” and is derived from the biblical story of Jacob and his firstborn son, Reuben. - google).
Or when naming the characters for a story where each character has their knightly title be a colour and are generally named for that colour I would google names associated with the colour and an aspect of their personality or a feature of them (kinda like how most got their last names)!
Whats YOUR method of naming OCs?