You do not need to use the Project Templates to start a new .NET Project.
The steps below show how you can start a new Project using Microsoft Visual C# 2010 Express. You will easily be able to adapt this to Visual Studio 2012 or other IDEs able to use .NET.
You need to open Visual Studio.
Then start a new project.
Make sure that this is an Empty C# project.
Once the Project has been created you need to add a reference to the SageCRM.dll.
You will need to browse to it.
Look in: C:\program files(86)\Sage\CRM\CRMDotNet\[crm version]\
And select the SageCRMNet.dll and click OK.
You can now add new classes to the Project. Make sure these are empty C# Classes.
Once you have done that you can clear out the default code and start to use the C# Snippets. (This assumes that the C# snippets have been installed on the machine).
You can now proceed to use the C# snippets to create the projects you need.