This should not take time but it is important. You must keep few things only. Many of them want to publish content on top site guest blogging, but some of them get successfully. If you write low quality content means reduce your bounce rate.
The most important think is you should write good & powerful content, then only accept your content. Find some authority website and get email from that website, give your suggestion, if you accept your suggestion, you can write and post.
This Guest post will improve your domain authority and high rank. Now a days not enough for link building and self promotion, use guest post.
High Authority Guest Blogging Websites List
https://www.shoutmeloud.com/join-shoutmeloud
http://contentmarketinginstitute.com/blog/blog-guidelines
https://blog.hubspot.com/marketing-guest-blogging-guidelines
http://www.forbes.com/fdc/contact.html
https://www.outbrain.com/blog/guest-blogging-guidelines
http://www.copyblogger.com/copyblogger-guest-post
https://techgadjets.wordpress.com/write-for-techgadjets
http://mashable.com/submit
https://techcrunch.com/got-a-tip
https://www.smashingmagazine.com/write-for-us
https://inc42.com/contact
http://elearnmag.acm.org/write-for-us.cfm
https://www.entrepreneur.com/page/236106
https://searchengineland.com/how-to-become-a-guest-contributor
http://readwrite.com/about/guest-posts
https://blog.kissmetrics.com/guest-blogging-for-kissmetrics
http://blog.inbound.org/guest-blogger-guidelines
https://www.sitepoint.com/write-for-us/
http://travelblog.viator.com/contact-viator/write-for-us
https://www.labnol.org/write
https://greatist.com/live/how-to-pitch-personal-stories-to-greatist
http://oilprice.com/write-for-oilprice
https://www.b2bmarketing.net/en-gb/get-involved
http://moneysavingmom.com/submit-a-guest-post
https://www.searchenginepeople.com/post
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