Adsense is one of the words best and most used online advertising network owned by Google.It is the most popular advertising network because of the reason that it is owned by Google and it provides high quality.Another reason for its popularity is that, it pays more than most of the other networks.
As I said, Google cares more about quality therefore, it is very difficult to approve your adsense account.Many people apply to adsense daily but only those sites are got accepted that qualify google adsense guidelines.
If you are one of them whose application is not accepted or you want to apply for adsense.Then, before applying you should make your site/blog in accordance with google adsense terms.
If you site is already approved for adsense, still you need to make your site in accordance with google guidelines if it is not.Because google can ban you anytime from adsense for life time.Therefore, there are a few things that you should consider for your blog.
You should read the google guidelines from the above link, but here I am going to explain the important things you need to take care of.
The most important thing you need to take care of is your content.It should be of high quality and unique.If you copy anything from internet even a single image with has copyright then you may got ban for it.Therefore before using any image, check whether it is copyrighted or not.And use your own written content.Do not copy from other sites.
Another important thing is duplicate content within site.If you have any duplicate content within your site, then you will not get adsense approval.For this, try to make categories and tags etc no-index.This will make your site free from internal duplicate content.
Similarly you can also use plugins etc to create your contact page.
Here is a list of important blog pages.
You site design also plays in important role in adsense approval.You should use clear theme that provides good user experience.If you use premium theme than it is good but you cannot afford premium theme then you can also use any good free theme.
Site age and traffic:
Google has written clearly in its policies that if you belong from some specific countries (that are listed in adsense policies) then you should wait for six months before applying for adsense.But it has been proved by many experiments that you can also approve adsense in less time, if you have quality content.
Same is the case with traffic.There is nothing about traffic in google terms but you will get easy approval if your site receives good organic traffic.If not, still it is not a problem because I myself have got approval with a site with zero traffic.So, according to my experience it should not be a problem if your site has quality content.
Sub domain and blogging platform:
One of the important thing which I have noticed is that, if you apply for a free blogger blog with sub domain, you will hardly get adsense approval until your site is of very high quality.But if you apply from a site with your own domain and self hosted wordpress, then you can easily get approval for adsense.The reason is that self hosted wordpress sites are more professional than free blogger blogs.
I have approved adsense account on my sites and according to my experience adsense approval Is not a big deal.The only thing which is important is the quality of your site and content.If you have good site with quality content which provide value to your readers, then adsense approval can be a very easy task.