Any post I write on my blog are written in my own personal words, with my own thoughts and opinions behind them. 
The majority of products I feature on my blog are bought myself, with the very little amount of money I have, student problems.
If I am lucky enough to be sent a product to review by any company I will mark it clearly with an asterisks (*) to make it clear that it was sent to me to review by the company.
However, I would never accept a product that I feel wouldn't fit into the theme of my blog or something I was genuinely interested in. I have turned down companies in the past as they did not fit in with the theme of my blog.
I always give my 100% honest opinion on a product I have featured on my blog. If I don't like a product, I will give an explanation as to why it has disappointed me.