How do you model this feature accurately enough to ensure the clips will interface properly with the phone?
using the indent command.. you can easily design a cover for samsung galaxy s4
That's definitely a great way to approach this design, though it relies on having an accurate solid-body to make the indent with. Also, the back cover that is created by indentation will be too large initially, though some simple scaling should fix that. I've found a few models of the S4 I will experiment with as a starting point, though I expect them to not be perfectly accurate as is necessary when modeling a shape that has to interface with another part. I'll be 3D printing what I design, so I'll be able to do a little iterative design to make it work. Thanks for the input abhishek!