Google support for FAQs and How-to
They provide structured data guidelines, which can be tested via the Structured Data Testing Tool to check if the page is marked up in the right way. Mark up must be done via JSON-LD, Microdata or RDFa to work.
The support section also highlights the importance of following Google’s Webmaster guidelines and Content guidelines to ensure that they are producing content that is of high quality and no manipulative behaviour or other misleading practices have been applied.
For creating How-to pages, creating a guide that has clear steps with an image for each step will help to create a How-to that is represented nicely in Google Search. Also, using video will help to receive good search results.
How to add rich snippets
To monitor the effectiveness of the Schema, you can use Google Search Console reporting under the Rich Results Status Report. This, along with using the testing tool, should enable you to identify what works well.
When implemented correctly, the new schema mark up for FAQs, Q&As and How-to pages provide an excellent opportunity to enhance organic listings, so it is definitely worth doing the relevant research to get a strong understanding of best practice.