I've read four articles in the past week about creating backup copies of your photos during the import/ingest process and had to throw in my two cents. I am a steadfast believer in having a systematic backup process for your photographs, but I also think a balance needs to be struck.
I happen to use Photo Mechanic and Adobe Lightroom to ingest/import my photos. Whatever program you use, it's likely that there is an option to create a second copy of the files you are importing or downloading. What this might look like in every day use is connecting an external hard drive to your computer and then downloading your pictures simultaneously to both your main computer (or laptop) and then a second copy to to your laptop as a back up. For me, I store all my photos on external hard drives (EHD) so I might have one EHD for my primary download and a second EHD as a back up location.
There's nothing inherently wrong with the double download, but here's one wrinkle to consider. You're only going to work on one set of photos and those will be the photos that are most valuable to you. All your hard work has been done on those photos, and they'll be the ones you want most to protect.
With that in mind, consider adding a couple of steps to the double-download approach: once you've completed your work on a given set of photos, copy that set to your backup drive. This way, all your work continues to be stored on two separate drives. After you've backed up the primary set of images you've worked on, consider dumping your original secondary download. To my thinking, there's little value in storing the unworked secondary download of photos, once you've backed up of your primary set of finished work, and the value of having 30% more storage space is worth it...at least to me.
Your personal approach to backing up your photos should be a function of how concerned you are about the potential for losing your photos and, of course, how valuable those photos are to you. I will admit there are some photos of mine which I have stored in as many as four separate locations...but very, very few. Generally, I have my photos in two locations and that's worked just fine for me.
Of course, this is my opinion and my choice of workflow. Everyone needs to choose a backup process that makes them feel comfortable and secure. This is the routine I've settled on and will probably continue to be my workflow for the foreseeable future.