Practical or beautiful - can it be both?

Most of my clients wants useful sites, for that I thank them

Redesigning a website to make it look better is a great idea. But only if it also keeps it useful or make it more useful to the visitor. There are few reasons to make a less useful website just to make it cool. But there are exceptions. 

Additional sites to a main site can be a options. If Nike wants to market a special shoe. They have it on their main website and there is a lot of information to find about it. But they want to give the customer a experience that a normal site wouldn't give. Then you can have cool colors, moving objects, actions you have to take like holder down the spacebar to see the shoe and so on. But this is rare.

Do I have to choose?

Not always, but sometimes.
I believe that almost every site can be made pleasing to the eye and also practical. I do this with correct spacing, typography, colors and images. The site then need a good navigation system. Easy to find links and logical naming.

But sometimes its hard, when the client has already made a color scheme that you have to use, that was made in the 80's. Need to show sponsors with their colored logo, have staff images taken with a potato and lighting from the north star. If this is the case, I go for 100% usability. Everything I do I try and think, how can this be even easier to understand. Is the visitor 100% clear on what to do here.

Beauty is not always how special the website is,  its a combination of all the small details that makes the site useful.