Get paid to write about any product or service you like.  If you can write a few paragraphs fairly quickly and enjoy writing your opinions for others to see, then you should consider writing reviews.  You only need a few paragraphs for most reviews or at least to get you started.  

As I said above, you can write about anything you like, anything that interests you or any product you have in the house.  People write about websites they have visited, websites they have bought a product off, different online services, electrical products, pretty much anything… even food they have in the cupboard.

You don’t have to be a good writer at all.  The websites want normal people’s opinions on things, not just professional writers and critics or people with very good English.  What the websites want, is normal people to write simple reviews on things that are easily understood by anyone.  You don’t need to be good with technical words or anything like that.  The idea is it is a website that anyone can go to, to read up on a product to decide whether to buy it or not.  

The best reviews I find tend to be the well structured ones where they have lots of headings separating the text into easy to read paragraphs.  

Just don’t write anything offensive like swearing etc.

Most websites don’t mind if you post the same review on more than one website, because as you wrote it, it is owned by you.  However, there are a couple of sites who don’t like you to do that so best to check terms and conditions for each website.  The two main review sites Ciao! and Dooyoo often have the same reviews on.