Start general and work towards specifics
The design sequence consists of several phases, each will progressively add the details that move the design toward the reality of a landscape that is both attractive and sustainable.
Always start with general ideas and then as the design ideas are conceived, move to specifics.
Do not be afraid to try many different plans. Let new concepts come and go with various designs. Take inspiration from other sustainable landscapes and implement those ideas. Have fun imaging how a new landscape will look and be used.