Get a manageable sized police box. Unless you have a jacket with pockets that are bigger on the inside.
Step B … no … 2.
Travel. Take your TARDIS on vacation (or even around your own city) and pose her in front of interesting sights and locations.
Step 3 or C.
Take a few quick snap shots.
Step 4 or D or iv.
Submit your TARDIS photo here along with a little description of where and when you were when it was taken.