Co-developing (Sharing and Saving) Suggestions for SL2

I know 360 would eliminate this co-development challenge, but is not in our non-profit's budget.  I used to do all development myself, but now have a new co-worker who also has SL2 and we will be working on a very large and important project together.  I'm hoping some of you have tips on how you make this work related to Articulate's strong recommendation to work on your local drive rather than a shared drive to prevent corruption? They warn against saving on both Shared drive and USB.  Any advice on whether it's better for us to take turns working on our local drive, then storing on shared drive so other person can access and save to her local drive, or is it better to save from my local drive onto USB and then she load onto her local drive? This is a very large project over the next two months so we would be doing this a lot! We would appreciate any suggestions!