Other than writing, what skills should a blogger have?

Coding is very helpful, as well as design skills. Other than that, learn the depth of SEO, and grow your social network!

A successful blogger should have compelling writing skills & interesting topics (content is king!) next to other skills which can vary from basic to advanced.

1. Internet user experience (account management, profile adjustment, posts, privacy etc.)
2. SEO skills (seo writing, writing for web, proper keyword choice, proper tagging, text optimization, link building etc)
3. Some creativity (image manipulation, image font and size choice etc.)
4. Basic code skills (HTML) for proper text-links embedment, image links etc.
5. Social media marketing skills (viral marketing, social bookmarking, link posting, community engaging etc.)
6. Being positive & original (informative, inventive, humoristic, entertaining, teaching). People generally like positive content more than negative or cynical bad news content.

1-Blogging is not limited to reading and writing. You have to be strong enough to do marketing of your content. The best way to do marketing of your content is Social Media and Blogging Communities. You have to drive readers to your blog. Apart from marketing your content you should also start marketing your blog. For this you have to do guest blogging. Create some outstanding guest posts and submit those guest posts on blogging giants related to your niche.

2- Search Engine Optimization is the supreme way to drive massive traffic to your blog. If you write irresistible content than you might be able convert your visitors to your readers. Improve your presence in SERPs and try to make your reputation for targeted keywords related to your niche. To improve your rankings in Search Engines you will have to perform off page and on page optimization. The big part of Off-Page Optimization is building quality backlnks.

- Traffic

-Mailing list 

easily no list no traffic . blog with out traffic = no visitor no cash

marketing as guess, 

WEB DESIGNING

 GRAPHIC DESIGNING

WRITING SKILLS

The most important "Skill" (if it can be said so) is the ability to think like your readers. One might be an expert in a domain but if the readers does not need the content being produced on the blog then it is of no use. This is the most important thing.

Other essential skills that a blogger should develop learning SEO (dont have to go too deep), marketing (crucial in today's time), disciplined (post at regular interval and not being lazy).