A collection of things I did not find in portage.
Just dump this into /etc/layman/overlays/my-little-overlay.xml and you are set:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE repositories SYSTEM "/dtd/repositories.dtd">
<repositories xmlns="" version="1.0">
<repo quality="experimental" status="unofficial">
<name><![CDATA[my-little-overlay]]></name>
<description lang="en"><![CDATA[Overlay with some stuff I didn't find in portage]]></description>
<homepage>https://github.com/twisted-pear/my-little-overlay</homepage>
<owner type="person">
<email>twisted_pear@twstd.neomailbox.ch</email>
<name><![CDATA[twisted_pear]]></name>
</owner>
<source type="git">https://github.com/twisted-pear/my-little-overlay.git</source>
</repo>
</repositories>