The majority of designers do not differentiate themselves from the rest of the world, meaning that we (designers) do not assume that we will have to explain ourselves for every decision. While we also constantly fall into traps of having our own personal taste and style. All of these attributes can sometimes get us in trouble, usually with clients. Keeping these things in mind can come as a huge help, for example; when working on a web-project you want to use parallax scrolling to set up the pages, when you suggest this to the design team they are not so sure because of their past experiences. To come to a proper conclusion you have to decide if the thing you are suggesting applies to the client, applies to the style of brand, or even makes sense for navigation purposes.
A huge part of making sure that your product is market-ready is doing usability testing. Cleaning out all of the gunk and grime that might be holding the success of your site back is huge for making the project work. There is a dramatic difference between usability testing and using focus groups. Usability testing allows for the site to work smoothly, focus groups give you the opinion and reaction of people.