SSDT/SSIS 2012 - How to automatically load some projects?
It's a little unclear what you're after, but here are two different features in SSDT (Visual Studio) you may want to take advantage of. These can be accessed by going to Tools | Options, then selecting the appropriate node from the tree as shown in the screenshots.

First, you can set SSDT to open the solution that was open when you closed the application the last time:



Second, you can set the default location for your projects, so when you go to Open a project, it automatically goes to this location first: