Do Search Engine Optimization! It is the process of improving the volume and quality of traffic of a website on search engines via organic search results for targeted keywords. On-Page Optimization (25%) first then next is Off-Page Optimization (75%).
Try less competitive keywords. You have to check how many competitor for that particular keywords and check how many authority site on first page. You have to analyze if you could compete with them or not. If not try to find other similar keywords. Try to find long tail keywords using Google Adwords Tool
This is very simple. Just post your link on social networking sites such as facebook and twitter. Social networking sites is the fastest and the most easiest way to gain organic traffic.