How can I prevent Skype from starting automatically on boot?

For the new 2017 version of skype that's impudent enough to add itself to autostart each time it's started (seriously? Never installing it on my own machine) it's enough to create a folder with the same name as a file it's trying to create:

rm ~/.config/autostart/skypeforlinux.desktop
mkdir ~/.config/autostart/skypeforlinux.desktop

Since it seems the answers here change all the time, as of an install of skypeforlinux from earlier this week (version 8.11.0.4), I managed to get the autostart to cease with two steps.

First, open up Skype, go to Tools > Settings and uncheck "Automatically start Skype".

Then, inspired by azeam's suggestion, go to (Xubuntu) Settings > Sessions and Startup > Application Autostart, and remove the item for Skype. I'm not sure if unchecking works; I tried that first, but it may have conflicted with Skype's internal settings when I tried it.

Had the same problem and the following seems to have taken care of it: go to (Xubuntu) Settings > Sessions and Startup > Session, find Skype and left click where it says "If Running" and change it to "Never".