Your question is the central point in the field of marketing. :)
The first thing you really need to do is identify WHO your prospective customers are. What do they want? Where do they live and work? Why will they buy your services? (Not what you think they want, what do they really want?)
Once you've gotten the feel for these kinds of questions, you can decide what the best ways are to get your messages across.
Passive marketing methods (signs, websites, etc.) only work when you prospects see the messages.
Word of mouth alone in a service type business is very slow to travel.
Track your activities for results and costs. Choose the one(s) that provide the best return for the costs in both time and money.
Good Luck!
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