1. your own domain on a self hosted hosting. 2. domain should be old. older it is, better it is. 3. 10 to 15 500 words articles.. 4. little bit link building 5. patience to get approval and try and try again Some south asian countries have restrictions that they can get accepted only after 6 months of domain registration
READ THE GOOGLE TOS AND WEBSITE QUALITY GUIDELINES on Google adsenses website, they have dozens of pages dedicated to what you need to do to get approved, it's failing to read these or simply not bothering to that results in most applications failing, as they are what your site MUST comply with to get approved. They should be your first port of call and NOT digital point. Fail to observe them and your application will fail, don't forget I told you so! That said honey213's points are good tips.