What BING finds very important for better ranking the pages? BING SEO for indexed pages, starting point.

Content and trust

• Domain age and authority:
  Bing tends to favor older and more established domains with a strong backlink profile and a clear niche.
  

Always try to write good content and link the good pages where users can read even more. If you write good content links will follow you.

Meta title, meta tags, headings and URL structure

• Keywords:
  Bing is more literal and exact-match in its keyword matching than Google. Bing pays more attention to keywords in titles, meta tags, headings and URLs.

Explain in limited characters your page title and description. You can adapt the title and description when you have more data from BING webmaster tools.

SEO and social media relationship

• Social signals:
  Bing considers social signals such as likes, shares, comments and followers as a ranking factor. Bing integrates social media platforms such as Facebook, Twitter and LinkedIn into its search results.
  

Share on social channels, pay the ads,…

Images, videos, audio clips

• Multimedia content:
  Bing is more visual-oriented than Google. Bing favors websites that have rich multimedia content such as images, videos, audio clips etc. Bing also has advanced image search features such as reverse image search, filters, collections etc.
  

Describe the image or video in URL, description, alt tags and in the content by words.

Don’t forget to index the pages with sitemaps or directly with BING WMT

More about Google SEO | More about Bing vs Google SEO

All above doesn’t mean to be working in ranking better. The BING SE algorithm is deciding of ranking. You just write and optimize, help them understand the content.
Check here your SEO report according the Bing in webmaster tools.