Best way to store photos

You don't tell us what your needs and constraints are. For instance, the best way would be to pay someone else to do it. How do you take pictures? iPhone or Nikon? Do you scan old pictures? Do you want to share pictures with others?

If you don't want to spend money, then the Mac's Photos app is probably the best around. You can put pictures in multiple albums, so the picture of "Aunt Ethel at the Grand Canyon" can be in the "Aunt Ethel" album with other pictures of Aunt Ethel, and it can also be in the "Grand Canyon"  album with pictures of other people at the Grand Canyon. And it can also be in a the "September 2015" album with other things that happened then. It takes no extra storage space to have a picture in several albums. As you can imagine, this is very powerful in organizing pictures.

I have pictures in albums, albums in folders, and folders in bigger folders. So, since I'm old, I have events in Month folders; those are in Year folders which are in decade folders. This keeps me from seeing 200 albums down the sidebar of Photos. (Actually, month folders are only for very busy months.) I also have Old Family albums based on my and my wife's family lines. So Uncle Joe is in events in years, but also in the "Smith" album and the "Chen" album from his two lines. Many of those pictures were scanned from those old family albums in a lost bookcase, so they are also in albums representing the physical books of pictures they came from.

These pictures also automatically appear in person albums and pet albums that are automatically created by Photos, itself. Photos also creates collections of pictures by location in a Maps view.

I use keywords a lot to help find things I might want. Any sort of thing that comes up more than a couple of times gets a keyword. Then I can search for "OurPets" to see all the pets together. I use star (★★★☆☆) keywords to rate pictures. Rating is really important, because I don't want to share all my pictures-- just the good ones. The simplest form of rating is choosing favorites, and that's made pretty handy in Photos.

In terms of "storing" pictures, I use Time Machine to back up my pictures (and everything else) every time I plug my Mac in at home. I also periodically drag my Photos Library to additional hard drives to archive them. So I have several hard drives for holding copies of photographs.

Anything else?