One thing I've learned in designing shared bathrooms for my own family and others is there's never enough room for all the goodies people like to use in the shower or bath! It's fairly common that we are asked to design a shower niche, but a couple of factors must be considered in the design:
Because shower niches are essentially inset boxes, the sides of the material will show. In the case of tile, the unfinished edge. Some companies make end-piece tiles that have a rounded or bullnose edge that's finished, but more often than not, you're left trying to figure out how to finish the edges in a way that complements, rather than detracts from the design.
To Feature or Not to Feature
The dimensions of a niche can impact the design, and questions come up as to whether you want the niche to recede, or be a feature. If a niche is large, such as one we did in a DC master bathroom, you don't have much choice but to make it a feature. In this case, we did so by using a pretty marble herringbone mosaic along the back.
A design choice I've been noticing more lately in shower in bath design forgoes the potential pitfalls of a niche for a more streamlined approach: a ledge. Smaller than a bench, a ledge is flexible in that it can provide for a good amount of storage with a minimal design approach. It's essentially a slight bump out into a shower or bath area, rather than a recessed box. If using tile, an edge piece would likely still need to be selected, but if you want to make a statement with a beautiful piece of stone, here's a good place to do it! Below are some great examples of shower ledges. I can't wait to incorporate one in my next bathroom design!