A quick tip Mark Cassidy helped me with – patching the Commands.config is something you may need to do when adding custom Sitecore ribbon buttons.

The contents of Commands.config get wrapped into Web.config when Sitecore initializes, so actually, we can patch Commands.config just like we would Web.config. The element you’re aiming for is sitecore/commands/command.

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <commands>
      <command name="item:clone">
        <patch:attribute name="type">ChrisPerks.Features.Ticker.Commands.CustomButton, ChrisPerks.Features.Ticker</patch:attribute>
      </command>
    </commands>
  </sitecore>
</configuration>

And et voila! Your Commands.config is patched.