No technical skills are required, but of course, you need to know how to draw with a computer program (like Inkscape or another SVG/vector graphics software).
Citoid is a service that provides citation information to wikis.
Either improve the existing logo which is not currently being used: https://commons.wikimedia.org/wiki/File:Citoid_logo.svg
The main problem is that logo has is it looks too similar to the current mediawiki logo. So you can edit it, or create a totally new one.
Please submit your proposal as a SVG file by attaching it in https://phabricator.wikimedia.org/T179691 (see the Phabricator help how to create an account and upload files). Once everybody is happy with it, add the logo to the mediawiki page at https://www.mediawiki.org/wiki/Citoid (see https://meta.wikimedia.org/wiki/Help:Editing for help about editing wiki pages).