Modernists often go for the floating-shelf look. This is fantastic for keeping an overall linear and light aesthetic; however, you've gotta master the art of styling to pull it off. Just group things in odd numbers, mix in different metallics, shapes, textures and finishes, and you'll be in good shape. If you're on a super-tight budget, pick up LACK shelves from IKEA; they're save you tons of money on custom costs and still offer the floating look.