Sorry I don't have any pics, but when Randal starts getting sleepy and spends her days curled up in a corner of her tank, I cut a doorway out of an upside down cardboard box to make a cave of sorts and put that down in the corner she likes sleeping in so that she has a bit of privacy while she's sleeping. As long as she's awake at all during the day I leave her heat light on (no UVB since she won't benefit from it in her cave anyway), but if she's sleeping through the day then all lights stay turned off (my house never drops below the low sixties). I peek in on her through the "cave" doorway in the morning and again before I go to bed to make sure she's okay and otherwise leave her be until she's ready to wake up and come out.
Edited to add: I don't purposely brumate my dragon, I'm not into breeding or anything, I let her dictate when she goes to sleep. I'm not sure what the procedure would be if you're trying to get them to brumate for breeding purposes.