A lot of companies around here have a standard charge for a plan. Consultation is usually free and then the design part starts. You tell them your fee, draw the plan, figure out the estimate, and meet with the client. They can view the design but don't get a copy of it until they sign the contract or pay the design fee. Some companies just charge them a design fee up front and they can keep the plan. You can also offer a credit on that fee back towards the job if they decide for you to do the work. I don't know about the other post stating a 10% design fee up front - a lot of customers would shy away I think - on larger jobs particularly. The only way you can get that type of money is if you are a large landscape architect. They always ream you on their charges. Also even if it is a small job a design always will help sell the job and give your crews a visual outlay on what to do. A small foundation landscaping drawing should not take more than a half hour to draw up if you are experienced. A full scale plan that included the whole site, hardscape, etc. on the other hand may take several hours to design depending on how elaborate it may be.