I get emails from bloggers every day asking for my help or advice - the good foundations for building a blog are as follows, in order of importance:
(1) APPEARANCE - YOU have to be satisfied with the way your blog appears. Of course, if it is a black background with tiny red lettering, good luck on snagging return visitors. Be sensible about choosing a template, and don't let the self-proclaimed blogging gurus dictate the look and feel of your weblog.
(2) BLING - The decor populating your sidebar(s) is part of your life, part of your weblog! For goshsakes, get rid of "Google friend connect" - it has been DEFUNCT since last fall! Get rid of MyBlogLog and any other outdated clutter as well! Any extra adverts, widgets, etc. are okay as long as they don't carry hidden pop-ups or links to self-downloading trojans. If you are displaying affiliate marketing badges and other icons, do a monthly check and delet any that readers aren't clicking on as well as any that aren't helping your blog.
(3) NICHE - Don't worry about finding one. Another thing blog gurus have people going nuts over. You;ll find your readers and they will find you. If you are hitting primarily on music or politics or television or pop culture or household tips, you've aleady "found" that niche.
(4) CONTENT - As much ORIGINAL work as possible. Links to things you refer to. Snippets and excerpts when you know a link may take a reader to a slow-loading or otherwise boring page. LINKS to images, videos and audio are ususally preferable to embedding. Embedding could slow your blog down and even invite DMCA Takedowns and all sorts of attention you don't want or need. Take your own photos and create your own original images whenever possible.
(5) GUEST BLOGGERS - Ask them to "guest" somewhere else - you want to avoid duplicate content as well as the issues cited in #4 above: too many professional guest-bloggers are idiots who will bring down your blog rather than build it up.
(6) SOCIALIZE - link to reddit, twitter, weibo, facebook, pinterest, etc. at your own discretion. Remove any links that aren't helping. See #2 above.
Think of your blog as a hub or portal. Look at mine. I can 'go anywhere' from here! I have both my favorite and most popular links to websites, blogs, services and tools I myself use, which I hope my readers will avail themselves of as well.
(7) COMMENTS - allow them but moderate them - I use very strictly moderated blogspot comments but also welcome Facebook comments which are a little more user-friendly. Saves me a bundle of time dealing with ridiculous comments and spam!