Making these finished my search and here's how.
My main reason for wanting a glossy tray was to sort out and tidy my everyday makeup area of my dressing table, which also shares space for my jewellery and office/computer area.
I chose the Ribba in high-gloss grey, size 13cm x 18cm - a RIBBA standard frame with a glass front. £2.25 - beats the £40 ones I've been looking at any day!
In general, the tray is the frame, back to front:
The cardboard backing now becomes the bottom of the tray.
I'm really pleased with the results and it's been a really simple and easy way in helping me organise some of the rooms in my home. So I couldn't stop -I went up a frame size in white for my bedside table:
If you wanted to add a bit of colour or fancy to the tray - the tops [which were previously the back of the frame] could be covered. Believe me, it took everything not to cover them in washi tape! If the tray is also going to be used for more practical to-ing and fro-ing - you can easily screw some handles to the sides [but I would recommend ensuring the sides are reinforced safely].