One method I've found useful is to simply do a search on Pinterest with your race and class, for example:
https://www.pinterest.com/search/pins/? ... e%20cleric
Clicking a specific image shows you similar art below it, too.
Another decent resource is specific art subreddits. A few I've found:
https://www.reddit.com/r/ImaginaryWizards/
https://www.reddit.com/r/ImaginaryKnights/
https://www.reddit.com/r/ImaginaryAssassins/
https://www.reddit.com/r/ImaginaryWarriors/
https://www.reddit.com/r/ImaginaryElves/
https://www.reddit.com/r/ImaginaryArchers/