Read some reviews. Not just one or two... but 10 or 20. Read the comments.
What kind of reviews impress you ... as a reader. Yeah, sometimes you realize it is not easy to write a really good review. So if you are kind of over-whelmed with some of it.. also think.... you know what? I have something interesting to say about the product and I don't think anyone has said it in quite the same way as I would. I should write a review about that.
Then do it.
Take a few extra moments to check what you wrote for spelling errors and make sure you have white spaces in your review. Don't have your paragraphs become really long and large.. break them up. Have some paragraphs be three or four sentences... others a couple sentences and others a bit longer than that. Variety is the spice of life and it makes your reviews easier to read.
Practice.
Write, write, write. If you have the desire to write. Do it. Write and try to get better and better every single time you write something. Improve your writing skills, improve your communication skills.
Improve for yourself. Improve for your best friend or your Mom or your Dad. Imagine your loved one reading what you wrote. Write so they would be proud of you.
Anyone can throw down some words on a page. Be better than that. Write because it matters to you. Write to communicate to others. Write for yourself.
I've been writing regularly since I could talk and I still have room for improvement. It's an evolving, changing, wonderful process and experience to write and write some more. There is an art to very good writing, but even if you are not trying to be artistic in your writing, strive to always be better at what you do. It's a good habit to get into in ever facet of your life. Practice it here with your writing. Let it flow over into other areas of your life.
Oh... and have fun!!! Make sure people know you are having fun. We like positive fun people. We like passionate people full of personality. We like opinionated people with strong views. But don't be negative just for the sake of being negative. Don't stir the pot because you are an unhappy crab and want others to be miserable too. Strive to be better-- baby steps...
Some people will be happy to give you their opinion on what you write. Some may not have the time or may not want to comment on your style.. but some will. Ask if you want to know. And don't have too thin a skin that you can't take some critical comments. Also remember... some critical comments don't have to be taken to heart or even listened to. People have different opinions and styles. Doesn't mean one person is more right than another person for everyone.
Have fun.
Keep reading. Good pointing. Discovering new writers.
Keep writing.