Lead Generation Campaigns are not just a fluke where you create ads and copies and hope for genuine sales enquiries.

Creating funnel approach can get you towards the goal of achieving genuine leads that converts into sales.

- Understand your target audience

- Create the target locations strategy

- Use detailed targeting and custom audiences

Facebook's Blog on Tips for lead generation

https://www.facebook.com/business/news/tips-for-lead-generation-on-facebook

Hootsuite's guide or gist on lead generation through Facebook Ads

https://blog.hootsuite.com/how-to-use-facebook-lead-ads/