Right now I usually find a pom.xml file on the web that has a pom packaging and copy and paste it to create my parent project. Then I used to run archetype:create inside the parent directory to create sub modules but archetype:create has become deprecated since then.
Any recommendations on how to create new Maven multi-module projects?
The easiest way I've found to do this is to use the pom-root archetype to create the top-level pom and then repeatedly use archetype:generate to create each module individually. This will automatically add the modules to the root pom (aggregator) and set the root pom as the parent pom for each module (edit: apparently some archetypes can have a hard-coded parent, but it works for maven-archetype-quickstart).
Here's the breakdown:
Create the top-level root:
mvn archetype:generate \
-DarchetypeGroupId=org.codehaus.mojo.archetypes \
-DarchetypeArtifactId=pom-root \
-DarchetypeVersion=RELEASE
cd into your newly created root dir.
For each module:
mvn archetype:generate \
-DarchetypeGroupId=org.apache.maven.archetypes \
-DarchetypeArtifactId=maven-archetype-quickstart \
-DarchetypeVersion=RELEASE
Note that -DarchetypeVersion=RELEASE above will automatically use the latest version of the archetype. You may want to add -DgroupId=... to each of those commands to avoid repeating yourself.
If you are working with the eclipse IDE you should use the m2eclipse plug-in. This is one of the easiest way to create multi-module projects. You can add a module to every maven project by creating a 'Maven Module-Project' within eclipse. When doing this you have the possibility to select a parent project. The plug-in does everything, means it copies the new module to parent module and modifies the pom.xml file.