First of all the content of your site should be unique!
There are many ways to building links and we have to use as many ways as we can.
Using some Authority Websites
Using some spam websites as well
Social Bookmarking and Networking
Apart from this, you need to have variation in keyword, if you are targeting only one keyword then it is wrong idea today, use some optimized and non-optimized keywords.
You can also use some keywords covering bold part of your web pages
But 50% links you have to build for your main keyword (there is one confusion about main keyword for example, if your keyword is:
link building service
then these keywords are also part of main keywords
link building services
effective link building
cheap link building services
affordable link building service
link building packages
So consider that all these keywords should be 50% of your overall link building work.
Other 50% would be those keywords which are appearing on your web pages, they may have searches, or may not have searches, for example, you have made some phrase bold on the same web page like
SEO is competitive
SEO is getting tougher
Ways to defeat penguin
backlink is very important part of a web site
price is too high for manual service
contextual links needed today
Apart from this you can use some keywords like:
know more about my services
my personal site
You need to follow above steps while building links.
Now how to build links?
As I said that you have to build naturally so build it naturally and don't leave any footprint.
First of all you should start from submission work like directory submission and article submission as they take some time in approval
after that you have to decide how many hours you have to give for this website and work daily.
If you have decided to give 2 hours daily so in 2 hours do it naturally.
few forum posts
you have to do it naturally, don't it fixed that you have to build 5 links from forum daily, it easily be caught, also, don't created only accounts,
for example, if you have created accounts on social bookmarking sites for 2 days then one day you can use some old accounts and submit your site and can create few new accounts too....
This thing can also be applied to forum posting, if you have crated account on forum and posted 10 posts, then next day on other forums but you have to use those old forums too on which you have posted already this way it would look too natural.
Also, use some sub pages of your site, you need to build links for these sites too but you have to focus on your main page....
Let me know if you have any suggestion!