Best Practice for transferring images to an Android phone? I switched from iOS to Android, and wish to transfer my pictures.

Where on the filesystem should I put the pictures? I first thought /DCIM/camera, but that's the directory for pictures shot with the phone.

/media and /Pictures seem to be appropriate, too.
I just want to set up everything in the best possibly way. I also want the pictures to be in different folders e.g. holidays, work, etc...

I have a Nexus 4 phone, if you need that to help me.
Please feel free to use a folder structure which suits you. It's better if you create a seperate folder for pictures, inside media folder or on the primary folder itself. (where the folders such as DCIM and media are located.)

As your title asks, there are no hard and fast methods to transfer data to your phone. Standard file transfer safety measures apply. 

About keeping seperate folders, do NOT use too many folders which might result in slowing down the phone. No matter where you put the images, the album app finds them. (Just make sure that you don't copy them in to folders that you do not know of)

Have fun with android.