Provide some good content or useful information for your targeted visitors. Traffic will automatically come. Don't forget to optimize the landing page, as it is the first point to invite your visitors for deep crawling.
Place a stop sign at the corner. Close the on ramp to the highway and set up a detour directly to your site.
Sorry, it's just way too general a question. Learn about SEO and marketing. There's a lot of information here on the forum about generating traffic to your site. The strategies and tactics you choose will depend on the goals for your site and your own skills or ability to hire someone with skills different from yours.
Also keep in mind that traffic isn't everything. If one person a day visits your site and buys something it's worth more than 10,000 visitors who hit the back button on their browser within seconds of landing on your site.
You can try writing articles and putting your links in you resource box. But in order to gain significant traffic those articles have to keep on coming. This will also help you with your PR.
Well, the best way to get targeted traffic is through Search Engines.
What is even better for Search Engines is that the traffic is not only targeted, they may be keen buyers as well.