In addition to everything said before, if you make use of the ticketing system it can save you a ton of headache trying to remember who to call, or where you are with this lead and what the next step is, etc.
I use it a ton during the Christmas season when you have a hundred different phone calls to make and installs to schedule, you simply create a ticket for each customer and when you get off the phone with them you update the ticket to what the next action is and when it is suppose to happen. Then you can forget it and the system will remind you automatically when to perform that action and you can look back and see exactly what has transpired from day one.
Or if a client calls in June and says they want you to aerate and seed in the fall you can simply create a ticket to remind you to call them the first of September with notes of exactly what they asked for and if you have any suggestions you would like to make to them as well.
There is a little more to the marketing than was said but it is definitely somewhat limited.
One other thing, you can set up document templates so that you can send off a preliminary proposal for clients to review and when they agree to it, one click and that proposal turns into a full blown contract with all the custom fields filled in and ready to be signed. You just have to put a little time into getting everything set up.