There are a number of things you can do.
First, I would edit the hub to ensure that it meets the new Style Tips and Goals that HubPages have setup. Add any maps, tables, quizzes or polls that you think your hub could benefit from.
Second, link it to any other hubs that you have written. If you think a reader would be interested in more than one hub because they are on a similar theme or topic, link them.
Thirdly, ensure that you have a number of high quality pictures that are yours, or correctly attributed.
Fourthly, do some SEO work on keywords and your title so that people can find your hub. I use Google Adwords and UberSuggest for my SEO.
Lastly, advertise your hub on Social Media. Google+, Facebook, Pinterest are all popular.
Hopefully, this will help you keep your hubs featured!