Choose a niche that you have an interest in, i.e one that you would be prepared to buy a product for and try it out in order to solve
a problem that you yourself are experiencing. This is important as you can easily write about it in a way that shows empathy towards the people you are looking to sell to.
Do some keyword research and write up enough material for 10 blog posts targetting keywords which you can realistically rank a new website for.
Post your material to your blog/website, but don't monetise anything yet. It is much easier to get backlinks from other websites if your site looks like an information provider rather than an affiliate site.
Create backlinks slowly and regularly - its important to not just backlink the home page, you also need to build backlinks to your inner pages, or else they will never rank. So, I would submit 10 articles to the main directories each with a link back to a different page on my site. I also use social bookmarking and web 2.0 sites to get backlinks to my inner pages. It is super easy to get forum backlinks to a site with no affiliate links/adverts too.
I usually wait for a couple of months before I add affiliate links, until my pages are scoring in the search engines.
My affiliate links will be placed within a new article which I mark as 'sticky', so it always remains the first page on my blog. This article will not be a review or anything like that, it will be my experience of the product I am promoting, and how it solved a problem for me. This is why its important to choose something you are interested in.
I use basic copywriting to create my money page. So, if my site is about dog training, I would describe how my stupid dog would do all sorts of bad things, how I was at my wits end etc... I would go into some detail about my problem. This is why it is important to use this for something you have an interest in - you must be able to show empathy with your site's visitors. I have lots of hobbies, all of which I am equally poor at, so finding niches is no problem for me. I then describe how I discovered product x, and the steps I took to train my dog according to this particular product. I go into detail to describe the situation now, how my dog is the best behaved on my street and hasn't bitten the postman for ages, all thanks to the stuff I learned in product x.
Again, I must say that this only works for a niche you are interested in yourself, and only if the product works as described. I guess you could lie about your experience with a product which you didn't buy, but I think that would be slightly unethical.
In my experience this type of pre-sell works better for me than review style copy.
Hope this helps someone...