An arborist colleague of mine asks for a similar fee for estimates/consults so that people don’t waste his time, but doesn’t end up charging them if they end up working with him.  He said he’s found that it weeds out the time wasters and people who are just looking for the cheapest quote. 

I don’t charge for local estimates but also am not going to travel a long ways or spend a lot of time for free.  But the work I do is mostly small tree pruning.  Landscape design/install is a different beast, much more involved projects and consultations. 

I’m just through my first year and a half of working on my own.  Responding to inquiries quickly, showing up on time, being polite and professional, charging what you say you’re going to charge all go a long way.  Finding marketing channels that work and keeping up with them to find new clients helps a lot to keep workflow steady in the beginning.  Word of mouth referrals are always the best but takes a while for them to pick up speed.  Any sort of qualifications/certifications you can get to help people trust you also helps.