May not be the best forum, but I'll start here. My wife and I take pictures and videos of our kids mainly on or phones for convenience. However, we do have a video camera and a decent Nikon camera. I've recently discussed backing up these photos so in the case our device fails, they don't disappear. What's the best method in terms of ease of use and affordability? I would like to back them up in two locations aside from the device. Multiple CDs, flash drive, external hard drive?

Last year I switched from external hard drives to a QNAP Turbo NAS.  it does a lot more than hold pictures and video but that's part of what it does.   I use external HDDs to backup the NAS now.

There're problems with every option it seems like.   This might be an interesting thread to hear how different people handle this issue.

ETA: I'm curious to know if anyone is using m-discs.  I have an m-disc capable Bluray burner and I gather the m-discs are supposed to be very durable and last a long time.

2nd edit:  Backblaze drive failure rate test.   67,642 drives in testing in 2016 Q3
https://www.backblaze.com/blog/hard-drive-failure-rates-q3-2016/

Multiple copies on multiple devices.

I have mine on two separate computer harddrives and two portable USB hard drives.

I should keep a copy of this. I re write it every couple of months.
The answer is “It depends.”  I shoot for a living so I need my photos. But I don’t value my photos any more that you do the photos of you kids, or your girl before she was your wife.

Lets talk in general. I hope you are saving your photos as shot somewhere and then making another file of copies that you have worked on (tuned) with whatever program you use.
You can ruin a photo over tuning it. If you have the original shot safely in another file, or drive, you can always go back to the well.

Keep in mind you will have completely update all of your data when formats change and evolve.
I still have some photos on floppy disks that even if I bought a floppy drive I would have to find a working windows 98 system to run the program to view them. I also have some photos in .ufo format that was a ulead program. So you have to keep updating all of you data. It will never end.

If you don’t have a ton of data saveing it on an external hard drive AND then copies to DVD's is a solution. I have external drives redundant in storage so that even if the house burns I still have (most) of my photos.

I am not talking about western digital or walmart drives those will fail not if but when.
While I was in photography school we had about 30% complete drive failures on that type of drive in three months.
I know an indi filmmaker that recommended CalDigit drives. They were going through terabytes of data every day with no problems. I have used mine for 5 years now as a daily working drive and have others for permanent redundant storage. (check amazon)

Lots of people are going to "cloud" storage while I see the attraction of being able to access the body of your work from about anywhere I am leery of having my work out of my control, hacks aside, I have seen photo storage site go out of business with little or no warning. Remember yahoo photos? My employer has some of its storage on flicker for public access to the photos. I have noticed in the last two years that there have been increasing issues with flicker that I think it has to do with it falling out of favor with the younger users, and that means less money in and less money for upgrades and newer servers. One day it won’t be profitable and it will go away.

OK, long answer there, so buy a good external drive. Buy as large and as new (fast) as you can and your computer will handle. Use it for your archives. Have a second day to day drive that you transfer data from it to the archive drive. Once the archive drives is full move it off site.
Start again.

When the formats and software change, convert them all again, or be sitting on photos in floppy disks.

SSD (solid state drives) seem to be the next wave, but are to expensive right now. Two years or so from now they will be the new normal.

This is one of those things where two is one and one is none.

I gave a talk on this and told them that if they wanted their grandchildren to see their wedding photos they needed to have them printed by a pro shop, or be ready to change electronic formats every time there was a new standard.

I just looked at the work drive I have here, a weekly paper, and since Oct 2013 I have 57,615 photos, Mostly RAW. These are all archived on another (caldigit) drive.

SSD will be my next go to. I saw Other World Computing had a SSD thumb drive that holds 480GB but it is $280. Too much for me to jump on now, but it shows where things are headed.

Someone said that this generation is the most photographed of all time, and when they are old they will have no photographs to show.

In a hundred years someone will find my M-Disks and re-discover my family photos.

Most of my distant cousins did not have any photos of their ancestors. They had to get copies from me.  In 100 years they will have all lost them again due to hard drive failure and multi-generational apathy so I'll share the old Dags and Tintypes a second time from the grave.

This, and if you have Amazon Prime, they will host your image files as a part of your membership.  I think jpgs, pigs, and tiff files are unlimited, and raw files may be, but I haven't used it yet.

Flickr Pro is also a good host for my final images.

I backup to multiple hard drives, I also do incremental backups to blu-ray discs for offsite storage

To start, I use a two drive RAID (RAID1-two 4 TB drives), which stays connected (but only on when I want to backup).  I have a USB 3.0 hard drive dock in which I can swap in various drives.  I use MS SyncToy in echo configuration and back up to the RAID about every two weeks, or if I have a large photo dump, immediately after.  The drive in the dock, about once a month.  Additionally, I have several self contained drives for use in specific circumstances.  Drives can go in a fire safe as needed.



I have several free cloud services (Google Drive, Amazon and MS Office) for my native .jpg files, but I put no documents there.  If I put raw files in the cloud, it would probably take a week + to upload, so I don't.  I back up all data to my drives (about 700 GB).

nooneimportant mentioned backing up original photos as well as copies post processed.  If you use Lightroom for post, this is not needed as LR editing is non-destructive, meaning that the original file is not changed.  The edits (what you see) are saved in the LR catalog.  You can always go back to the original (and make as many changes as you want and save them all in the form of data).

I know the argument that what I do is not "backup".  I am comfortable with what I do.

Now, as a new quadcopter owner, I foresee needing a few additional TBs of space for video.

I have my photos on my computer hard drive, amazon photos, and an externall ssd. At a minimum you want 2 copies at home and one copy that is stored off site.

The truth is there is no perfect archival level storage option currently available for digital photos and video.

I use this drive.

https://www.bhphotovideo.com/c/product/1217667-REG/samsung_mu_pt500b_am_500gb_t3_portable_solid.html

This. Plus multiple storage formats. I had a networked external hdd that I used for backup. I trans-coded all my digital video camcorder movies and stored them on this plus making copies on DVD. After a move, the dvds disappeared, the network hdd failed, and my original dv tapes have lost their images. I don't have videos of my kids growing up and my wedding video is gone. 
Make DURABLE copies of everything and store them securely. I'm building a freenas server for all the new videos of the grandkids. (And any movies I make backups of. )

It's good that you're thinking of this before you lose years' worth of digital artifacts. It is not a pleasant experience to tell your wife that half a decade's worth of video of the kids are lost. 

There is some good advice in this thread and my addition is the "3-2-1" strategy for backing up digital artifacts: 3 copies on 2 different media and 1 copy off site.

3 copies: One is on your computer, one is on an external drive, and another is on optical media [Blu-Ray/M-Disc, DVD, etc.].

2 media: Hard drive is one media, DVD is a second. Tape also works as a second media type, if one were so inclined.  

1 off site: Whether you swap a pair of hard drives with your family across town or place DVDs in a safe deposit box, you want to make sure a copy of important files is not at risk should your home (or even your neighborhood) is lost to a major catastrophe (fire, flood, BLM riot... you get the point  ). Yes, cloud-based backups count as off site.

I recommend CrashPlan for online backup. This is a real backup solution (versus a file hosting service like Google Drive, OneDrive, Amazon, etc.).

I think you'll appreciate reading "The DAM Book" by Peter Krogh. He covers backup strategies from a photographer's perspective and shows a number of strategies from simple to complex.

I use external HD's but I have to recommend going in the cloud.   It's time to embrace cloud storage if you haven't .  I moved 60,000 pics to google photos and never looked back.  The only downside is it's not the best for photo editing.