Check licensing and references. Check for certification requirements in your area. This is especially true when it comes to elements with safety ramifications, such as decks and retaining walls. If certification is required for your job and your area, confirm licensure for every pro you consider. When you've narrowed it down to two or three finalists, get references from each and be diligent about checking them. If past clients are pleased, odds are you will be too.Provide helpful documents. Although your landscape pro will conduct an initial site visit and walk-through at the outset of the job, he or she will most likely need a copy of your property plat in order to start work on your design, especially if there are building permits involved. You may also be asked to fill out a questionnaire or other information sheet to help the pro understand your needs and requests as thoroughly as possible.