I like to do a lot of research before I buy. I start out attracted to the look of a product. It gets my attention. Then I check out the size, to see if it's even possible for me to use it. Once I've decide that is is I move on to the material. If it looks like something I'd use I look at reviews. I look at the good and bad they present, and decide if the problems are something I can live with or not.
I've seen a lot of products that the reviews have made me reconsider purchasing, but just as many where I figured I could compromise on the downsides and bought the product anyway. If every thing else looks good, and the reviews don't give particularly compelling reasons not to buy, I typically will.
I also like to shop around the different lines, check out comparable products and whatnot. I feel like If I'm spending my money on something I want to make sure I'm getting something I'll like.