While a web agency is working on a web site there are some good practice to keep in mind and to apply in the process.
First of all, a good website needs to be accessible by the most of the users. There are several groups of users to consider, such as those with old computers, those who have some physical problem (such as blindness), those who prefer to surf on the net with a smartphone or a tablet and so on. Every group has specific needs and the web agency needs to keep all of those needs in mind, as you never know in which of those groups is your next customer.
Regarding accessibility some of the issues to be solved are about browsers, screen resolution, download speed (a quicker website convert more than a slower one) and technology to be used to create the website.
Quite important is to think about contents. They are fundamental in every website for several reasons, among those the two most important are allow users to better understand what a website is about of and allow a website to rank better on search engines (specifically for this reason contents are also known to be “the king”).
We can also say “the” good practice is to realize websites thought mainly for users: nice to see, easy to use and rich in informations. This is the “recipe” for your online success.