I'm starting this thread for those who are considering sending in an application under self-employed category in 2018.
@BaNana82 has been extremely helpful so far sharing his own process and timelines. I'm currently collating my documents and have the IELTS on Jan 20.
Once I receive the results, I will be sending my application in. I'm applying under 5121 - authors and writers. Though the current processing time on CIC website says 48 months, I've met several people who received responses within a year or less so don't let the time discourage you as it did me the first time I considered this in 2015.
You can find occupations that fall under self-employed category here -
http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=291&top=6.
Let's all support each other as we proceed on this journey in 2018...