I like to support (or at least acknowledge) users who have JavaScript disabled in their browsers. The <noscript> tag is a great way to provide alternative content or messages for these users. Here are the snippets that I use.
In the header:
<noscript>
<style>
.scriptonly {
display: none !important;
}
</style>
</noscript>
Then, in the body, add the scriptonly class to any elements that should be hidden when JavaScript is disabled.