Website design field is ever-growing and constantly changing. What design element was once considered to be the soul of a website becomes obsolete in a matter of few days. Sometimes these trends are launched due to the necessity such as responsive device, while others are simply industry shifts such as the transformation of flat design to modular design.
The decision of implementing these trends should depend on the requirements of your business and your target audience, and should not be simply based on “what other popular sites are implementing”.
As a matter of fact, if a website design trend quickly becomes outdated, how your website supposes to last a lifetime with the same trend.
Having said that, there are certain website design trends that you should be extremely careful about.