There are those, like myself, who appreciated the art done for those trifling girly pin-ups like Elvgren and Vargas and that lot. And it's always a treat to see into the working methods of really great technicians. So here's a video somebody put together showing side by side shots of the photo reference and the final pic. You can see where they got the models as close as they could and then did some things to lift it out of the realm of the mundane and place it squarely in the realm of idealized, fanciful celebrations of female allure in all kinds of settings -- like creating the best vacation scene ever. . . They used photos, yes they did. And they projected or traced, and also improved on the photos to bring it up to their levels of artistry.

Have some fun. I sure did when I stumbled over this YouTube video.

https://www.youtube.com/watch?v=uRJAu_br7YM