For some reason I don't see many people in the #fediverse talking about #openclipart , an online media collection of more than 160 000 vectorial graphics, entirely in the public domain which can be very useful for your projects.
You can read more about it visiting the website and reading the corresponding Wikipedia article:
To see some interesting #openclipart #art examples you can follow these profiles there, beginning with #liftarn
Another interesting #art #openclipart profile could be #j4p4n:
And another interesting #openclipart #art profile (specially for roleplayers) could be #nicubunu: