Lightweight CyanogenMod 13.0 - Samsung Galaxy S2
Observe .repo/manifests/default.xml for a list of components included by default in the build. For example if you want to remove 2 live wallpapers "Basic" and "PhotoTable", then you'll find these corresponding lines in the file:

  &lt;project path="packages/screensavers/Basic" name="CyanogenMod/android_packages_screensavers_Basic" groups="pdk-fs" /&gt;
  &lt;project path="packages/screensavers/PhotoTable" name="CyanogenMod/android_packages_screensavers_PhotoTable" groups="pdk-fs" /&gt;


Now create another arbitrary xml file in .repo/local_manifests. Edit it and write:

&lt;manifest&gt;
  &lt;remove-project name="CyanogenMod/android_packages_screensavers_Basic" /&gt;
  &lt;remove-project name="CyanogenMod/android_packages_screensavers_PhotoTable" /&gt;
&lt;/manifest&gt;


Do similar edits for all components you want to remove. Save, sync repo and build.

Do note that many items are crucial and can't be removed without introducing errors to building or using. Despite you wanting an extreme barebone experience, I advise against doing so, at least during building.