Before I began, I read the script (from The Complete Guide to Godly Play, Vol. 4) onto a recording which I then listened to as I worked. Once I'd finished, I listened once or twice more while I physically acted out the lesson, moving the pieces around, and finally tried it without the recording, speaking the script myself. Way back in training we tried that, having one person read the script while another moved the pieces, but I'd never tried using a recording of myself for practice before!
The materials were far from ideal. I cut a cross out of cardboard packing material from our recycling pile. Having no paint to hand, I used magazine clippings of purple on one side, and white felt on the other.
In the end, we had no children at church and I didn't present the lesson. But you know what? For one-time use, in a pinch, I was much happier to have far-less-than-perfect materials than not to have had any at all. I enjoyed this little project as a Sunday task, and I felt good having something to offer children if any had come along.
I've heard it said, "Perfect" is the enemy of "Done". Godly Play materials should always be made with love, as beautifully as you can. Really, they should be as good in quality as the objects you use for liturgical purposes for adults (as nice as your chalice or communion trays, as nice as the Bible on your lectern). But don't let that ideal prevent you from doing the best you can.