Sparx Systems Enterprise Architect is a great tool, but you can make it even better by customizing it with your own add-ins.
Below is a list of tutorials about writing add-ins for Enterprise Architect. Best to read them in the proposed order.
Tutorial: Create your first C# Enterprise Architect add-in in 10 minutes
The first baby steps in creating your own add-in
The complete Enterprise Architect C# add-in template
Making your life easier with the add-in template
Testing and debugging your Enterprise Architect C# Add-In
You’ve created something but now you need to see if it works (or why it doesn’t)
Tutorial: Deploy your Enterprise Architect C# add-in with an MSI package
How to make others happy with the fruits of your labor
How to use the Enterprise Architect Add-in Framework
Getting serious about add-ins? Using this frameworks saves a lot of work and enables re-use of your hard work.