1. Use a different SD (memory) card for each device
When you’re using multiple devices, sometimes they require you to format your SD card, which deletes all of the files on it. If you’re using only one SD card and you need to format it, then all of the previous files you had on there are now gone. To avoid this, get multiple SD cards and save your work to your desktop or an other hard drive.
2. Create folders based on dates or topic
Once you have all of the shots, or audio you need create a folder based on the date you took it or the subject. For example if you were shooting on October 4, 2014, maybe name the folder 10\4\14 video, 10/4/14 audio, etc. Or you can do it by the subject, like if you were taking pictures of a cat maybe call the folder cat_photos.
3. Do the same for file names
Then you can do the same for individual files. When you upload them to your computer they usually already have some file name that consists of letters and numbers, and to avoid confusion, I go through all of them and then change the names of the files I want to keep.
I hope this was helpful, if you have any questions, leave them in the comments below.