I am glad you asked, I was on a very similar situation myself last week, my panther female was restless, wondering the botom and I put a little plastic container inside her cage hoping she would laid there. (the container was 12x12x8inches) However after a few days she was not showing any interest.
What did the trick was: I went to home depot and bought a big grey trash can, I would say it was about 3ft high, 2ft wide. And I bought a small pack of peatmoss.
I filled 3/4 of the can with peatmoss. Add water to the peat moss and get it damped, not too wet. It will take a lot of water but just give it the consistency of planting dirt.
Since I didn't know how long was going to take for her to lay eggs, I planted a small plant in the middle, I put a couple of branches for her to perch and then I sprayed the whole inside, so she had humidity and water to drink.
I placed the can below my uv lights. And then I put the female in, I left the room and I started just picking trying not be noticed, not to disturb her.
15 minutes after I placed her she was digging! To make the story short, she started around 9am and she finished around 5pm. She laid 22 eggs.
Once you see where is she digging, you can leave her alone. This helps so it's easier to digg out the eggs.
I am at work right now, but as soon as I get home, I'll try to post pics for you to see.
Good Luck.
P.S. I spent $18ca on my "laying" setup