I would start with SEO. Get a few basic links on popular website, from there I would advertise. Really, you just have to be willing to invest and test things out. Not everything is going to work, but once you get the right formula, it is golden. You have to increase your advertising to bring in more traffic. People want to make it harder than it is.
Do your keyword research and optimize your site for high search - low competition phrases. Get back links and use social media to get high ranking and more visibility.
I get 35 a day on avg. on one site. Why is this your goal? Do you intend to convert >80% to adsense or affiliate?
1. Write quality content that is useful to your visitors and that is keyword rich for search engines. 2. Keep your site updated regularly. 3. Add your site and the sitemap to Google Webmaster Tools. 4. Start promoting by adding it to your profile at Digg, Stumbleupon, and other social media sites. 5. Start writing comments on relevant blogs and relevant forums. These 5 steps will set you on the way to 50 visitors a day. Just keep doing it, don't give up after a week or two, it takes long time to build consistent traffic.
The easiest way to get 50 a day would probably be to do seo. The other thing to do would be to have a whole bunch of links to your website, and 50 people are bound to click all those links
The easiest to get 50 or even 500 a day is to do traffic exchanges. Now, not all traffic exchanges are made equal - some are good and some are crap... so chose wisely