To meditate using pictures, you need to find some photos, your own or online, that speak to you of God's presence and love. There are so many to chose from that it may be hard to pick one. If you are on Facebook, your friends no doubt post many pictures that are inspiring and some even have verses already written on them to help you start a meditation.
After you have a photo chosen, print it out large enough so you don't have to squint or blow it up on your computer or tablet screen. Then
Sit quietly with the picture
Enter into the scene
Look at where God is present
Breathe slowly and allow yourself to just be still and quiet with the picture
If there is a verse or saying on the picture, reading that may give you another depth of meaning for the picture.
Try finding a picture yourself and sit with the image to see what God is saying to you.