If you just want to make a simple and fast HTML template, then whatever works for you most efficiently is fine. If you want to really learn and understand what's going on "under the hood", then writing the raw HTML and CSS with a text editor is the way to go. But that doesn't mean you need another editor: unless something has changed since the few years ago when I last used it, doesn't DW have a source code mode where you can directly write/edit HTML (etc.)? And sometimes the fast-and-easy approach makes perfect sense, and other times getting down in the weeds to optimize, customize, and make the page do exactly what you want is what you need.
In my case, I'm mainly a server-side developer, and I use Komodo Edit both at work and at home (trying to get work to invest in Komodo IDE 
). It's "just" a text editor, but has syntax checking, syntax highlighting, auto-complete and tips for a whole slew of coding and mark-up languages, so I use it for everything from PHP, JavaScript, HTML/CSS, SQL, and JSON, to name the most common things I use.
