If you are fortunate enough to have a site with an existing stream or grouping of trees, be aware of them, as they are great design elements and add a sense of nature and dynamism to any landscape. Development around trees, creeks or streams is highly regulated in some jurisdictions.
If you are looking to purchase a property that has a large dry creek running through it, be aware that there could be setbacks required, greatly reducing the buildable area of your property.