Decide on function
The first thing you need to do is decide whether your outdoor shower is going to be an outdoor bathroom experience, or simply a place to wash off dirt and sand. The type of function your outdoor shower will perform will influence the type of structure you need to build, the drainage requires, and the location of your shower in your yard.
Check with your council
Before installing an outdoor shower with both hot and cold water, be sure to check the regulations around such outdoor structures with your local council. Some councils require that an outdoor shower meet certain requirements, while other councils have very little rules at all.