What to place beneath the vegetables before placing them on the baking tray? In order to prevent their surface from burning, what can be placed beneath vegetables to be roasted before placing them on the baking tray?

I am thinking of applying oil to the tray, but I'm not sure if that's enough.
I usually put tinfoil down and then lightly oil it. If done carefully, the tray stays clean and doesn't need to be washed and the foil can be thrown out (or used for a second batch of veggies if you have one).