I do estimates for free and I do a lot of free consultation advising people about their options and evaluating their landscapes.
When preparing an estimate requires work and research, then there should be a cost for it. I do not do the kinds of estimates that should have a cost.
I do design for a fee. In order to get paid to do design you need to be able to produce a design that has value. That means it needs to be a design that satisfies the clients needs but also has the expertise needed for the job. It also needs to be complete and detailed enough so that another professional could install the landscape.
In many cases I do the design work for free and build in the cost to my estimates. If I do the design for free, it is my design and I own it. So they do not get it unless I do the install.
I do a good bit of consulting for free, but I am doing more fee based consulting. It has taken a lot of experience and training to develop the skills to provide consultation that has value and can be provided on a case by case basis.
It comes down to the fact that you can charge for things that have value. You cannot charge people for estimates, designs and consultation that does not have value.