It's a nice mockup but was actually wondering was what you would do (in Photoshop) to the original images of those objects (assuming they were normal photos of a phone, keys, watch, etc) that would give them that illustrative quality. Not the mock-up itself. Though I am curious what effect you used to get that towel fabric look.
Unfortunately, I used a non native Photoshop tool. Specifially Alien Skin Eye Candy - animal fur, but with the original image selected.
To do it with native Photoshop tools, I'd probably use a displacement map. Start with an image with the towelling material, and produce the displacement map from that. Then apply the map to the image you want for the towel.
Note that in my example I started with a flat rectangle, and laid it down after applying the texture, so that the texture had the same perspective as the towel.
Or you could pay $90 for Eye Candy. I only bought it a couple of days ago, and I am really into it right now.
[EDIT] Note, I deliberately upresed your image because I wanted to start with rougher outlines. I think that would be even more important if using the displacement map method.
Thanks for the links Trevor. The Photoshop/Displacement link doesn't really create the effect that I want (it seems to take an object, make it transparent and composite with another image) and the alien skin one seems to be about creating a fur effect. These are great to know, but I'm less interested in learning about how to create the fabric as I am how to take an image and add a filter or something that will make it look like an illustration. Any suggestions on that would be greatly appreciated.
So I was getting hung up on the beach towel, but you were only interested in the duotone images on the towel? If so, that is very easy indeed.
Open an image. If you want a plain BG then you'll have to select the object and copy to a new layer, and fill the BG with black or white.
Then go Image > Adjustments > Threshold
This will produce the effect in the centre image. Note you can addjust the point at which the transition happens with a slider in the Threshold dialog window.
You might find the effect very harsh and with some jaggies. If that is the case, use some Gaussian blur to soften, and if you like, harden it up again with levels or curves.
If you want a BG colour other than black, add a new layer and fill with that colour. Then set its blend mode to Lighten.
You can do a similar thing with Filters > Artistic > Cutout and setting the number of levels to 2. Not as nice as Threshold, but the way to go if you want more than the simple on/off affect of Threshold.
This is great! Thanks Dennis!