Unfortunately, there are many, many ways to get offline clients.
There really is no "best way" to accomplish this.
It depends what your personal strengths are, what products or
services you intend to sell and how you are going to fulfill your
contract (either by doing it yourself or outsourcing it).
We use cold calling on the phone as our main source of getting
clients. We also face to face cold call with great success. These
are just some of the ways to get clients.
You can get on free online advertising websites like craigslist,
backpage, pennysaver, recycler, etc.... and look for ads from
business owners that are looking for website help, internet
marketing help, email campaigns, mobile marketing, etc.
They will usually leave a phone number you can contact them
at (first choice) or an email (second choice).
Now depending on your sales skills, you should be able to
get an appointment out of every 5 to 10 calls. Then you'll
have to make a presentation and close them to hire you.
Other ways of getting business owners that we have use
with good success is direct mail, emailing the business
owner, going to Chamber of Commerce meetings, going
to Meet-Up meetings, seminars, webinars and sending
out free reports.
There's no easy answer to your question. But I can tell
you from experience, that you should focus on one service
or product, learn as much as you can, learn how to sell
it (or hire someone to sell it for you) and learn how to
deliver it. From there, you can start adding services as
you go along. The only hard part to this business is
staying focused and taking the first step.
Forum members above have given you some good
suggestions too. Now it's up to you.
I hope that gives you some help. Best of success
to you.