Update your website and social media with photos of your events. Action-oriented photos catch the most attention.
Try to maintain frequent activity on your social media. Many recommend daily postings.
Maintain an up-to-date calendar on your website and be sure content (especially on home page) is current and reflects frequent updates. Your league is constantly doing things and your sites need to reflect that activity.
Encourage existing members to talk up the LWV in other groups, organizations they are in, such as book clubs, church groups, fitness classes, at work, etc. And make sure the existing LWV member gives out the website address to join.