non destructive

I have completed at least three final QTVR's and am very pleased with the results. I have found them very rewarding and am pleased my content was successful. The main thing I have really learnt is non destructive editing. unfortunately some of my psd files have not been saved correctly and i have saved over the previous files. so the adjustment layers, masks can not be seen. As this is an important thing that has been lost instead of starting again I want to go and take more photo's so I will then have the correct amount of un-flattened files to show my working. this will also give me more final QTVR's as a final outcome.