Here are two more plugins I have made available today for NetBeans IDE 8.1, specifically for working with HTML:
Sources of the above, Mavenized and waiting to be forked:
Both are in the process of being verified, once the community has completed that process, they will be available under Tools | Plugins. Until that moment, just go to the pages above, click Download, then go to Tools | Plugins and install the downloaded NBMs via the Downloased tab.
What do these two plugins give you, exactly? When you open an HTML file, you should see the HTML Palette (or press Ctrl-Shift-8) contains a bunch of new HTML5 snippets, as described here:
Picture of how you can set things up:
The other one is more experimental and may not work exactly how you'd like, though it's worth giving it a try. It is a JavaFX WebView on top of the HTML Source Editor, as described here: