You can update the page regularly with useful information and share in different related groups, share page on other social media sites, if you ready to pay amount go through paid likes etc...

Contests
Coupons
Facebook Ads
Attraction.

To increase likes you first invite your contact to like the page then add most attractive post to attract viewers to share the post that all will help you to get more likes.

To increase likes you first invite your contact to like the page then add most attractive post to attract viewers to share the post that all will help you to get more likes.