The question is nearly impossible to answer in a vacuum. By that, I mean that there is no single "best" way to get traffic. It depends on who your target audience is, and what you expect them to do when they arrive.
For instance, if you want people to buy something from you, you need much "warmer" and more motivated people than if you're just asking them to read an article or perhaps subscribe to a newsletter. The more expensive the stuff is you want them to buy, the "warmer" and more motivated they need to be.
How you reach these motivated people depends on what you're offering. You need to find out where your prospective customers are spending their time online (and offline) and make sure you're where ever they are.
This might mean running print ads, posting to Pinterest, doing the radio talk show circuit, joining (and actively participating in) discussion forums, attending local meetups, running Facebook ads, keeping up with a business-related blog, writing articles for industry publications, etc.
You will probably have to do more than one thing. Most of the people you run into (online or offline) are NOT going to be "warm" motivated potential customers. Your job is to turn them into a good prospect.
The problem for a lot of people is that they focus on more
traffic. You really don't want more
traffic, you want better
Seriously. What's the point of having 10,000 people trooping through your website every day if not a single one of them
ever does whatever it is you most want your visitors to do? The trick is to find and attract the right
traffic, and then do everything right to convince them to buy/subscribe/join (whatever it is you want them to do).
You will almost certainly find if you do a better job of targeting your prospects and converting them to customers you can thrive with much less traffic than you initially thought.
Think about this: would you rather have 100 visitors with a 5% conversion rate, or 10,000 visitors with a 0% conversion rate? A 5% conversion rate (or better) is very
doable, even for a small-shop/one-person website.
Stop thinking about what you need to do to get MORE traffic, and start thinking about how to attract BETTER traffic (and how to make better use of the traffic you already have). You'll see a much better (and faster) return.