I've been busy making digital collages, mostly using a combination of my own photographs and images from vintage Kodak ads, vintage sewing pattern packets, and old ads or images of 19th century ladies in swimming costumes and bicycles. Finding the images is just the first step.
I separate the people from the background using Photoshop, which can be tedious, but once I have them done, I save them as PNG files and they are ready to go for the next collage. For the Greenhouse picture I ran my original photo through the Waterlogue app on my iPhone. I do most of my actual design and composing using PicMonkey because it's much easier than Photoshop for this kind of work. For me, anyway.
Some more examples.