In most cases, taking the chronological approach makes the most sense. Depending on the number of photos you have, you may want to organize by decade then break it down into years. The advantage of sorting chronologically is that it will be easier to find duplicate images, which you can then discard.
Some old pictures and prints are incredibly rare and valuable, but age is no guarantee of value. There are thousands of 19th century prints on the market, many of which are small decorative bookplates (pages torn out of books) that may be worth a small amount if their subject has commercial appeal.
If you sort chronologically, photo storage boxes or a photo book might be what you need. A pretty scrapbook will allow you to add some personality and really tell a story as you create a keepsake that will be treasured for years to come. Glassine envelopes are also a good option.
The easiest way to do that is to digitize your whole family archive and keep it in a cloud storage. It might be truly tedious to digitize thousands of photos, but trust us - keeping your family history intact is worth it. Besides, no one is forcing you to digitize all your photos at once.
In your photo managing system, create folders for each year of photos you have. Then place the corresponding photos in these folders. Once you've sorted your photos by year, go into each folder and create subfolders. You can label and further sort your photos by month, event, vacation, etc.
But what some might not know is that those little brown negative film strips can be digitized as well. And in a lot of ways, keeping those negatives is your best bet to preserving your memories as they can be used to create new physical prints or digitized copies.
If you need a lot of storage space or want to make backups, you can use an external hard drive. Another option is to store your photos in the cloud. Windows has a built-in option called OneDrive, while Macs use iCloud.
You also can make a photo book as a backup of your all-time favorites and store it somewhere like a fireproof safe deposit box. But a digital backup is the best way to safeguard your memories. Even if your computer is lost, you can still access a cloud-based account with your photos attached.
Start by sorting the photos chronologically. Any other sorting option is just too confusing and crazy-making. Think big picture by dividing first into two piles according to century. Next, sort each pile by decade—even if that requires a wild guess—and so on until you have them in general order.
Consider shredding old photos instead of just throwing them out (after you've digitized them, of course). Thieves can use your photos maliciously, and even if they can't steal your identity using old images, it's still a good idea to keep them secure.
Donating your old photographs is a great way to clean out your photos without feeling like you have betrayed your family. If your photos are based around a specific location or family, check with that location's historical society, genealogical society, or local library to ask the best way to donate the images.
Sorting everything by decade into labeled bags or containers (1960s, 1970s, etc.) is a helpful way to restore some order to large collections. You could sort each decade even further and make categories for different years, places, events, or family members.
Use preservation-quality folders and boxes that are large enough to fully enclose and support the photographs. Avoid using acidic cardboard shoe boxes! Photographs in poor condition or that have special value can be individually stored in stable plastic sleeves made from preservation-quality polyester or polyethylene.
Early tintypes were in small, hinged cases like the daguerreotypes and the ambrotypes. However, the cases were soon replaced by paper sleeves. Often today, tintypes are found in one's collection without the sleeves. In the 1890's the tintypes were popular in carnivals.