Follow the following steps to create a module using Liferay Plugin SDK in Liferay 7.0.

1) Install Liferay IDE in your eclipse (if not yet installed). Follow this to install Liferay IDE.

2) Open eclipse and create a new Liferay Workspace Project. Select File -> New -> Project

3) Search 'Liferay' and select 'Liferay Workspace Project' and click Next.

4) Enter the workspace project name and click finish.

Don't worry, You won't get the error that I got until you already have a workspace project with this instance of eclpise. Please notice, an eclipse instance can have only once Liferay Workspace Project. Click finish and wait for some time, let it finish.

5) Click 'Yes' if it ask to change the eclipse perspective into 'Liferay Workspace'.

6) Congratulations, project is created successfully. 

7) To create a module, right click on project and select New -> Liferay Module Project. Enter module name, select build type (There is gradle support only this time), select template type and click next. I'll write another blog in order to explain the templates type.

8) Enter portlet class name and package name. Click Finish.

You can provide the properties to configure the portlet.

You can build and deploy the portlet now.

That's it.