Flame texture
We had a demo today on how to create a basic flame or lava texture.
First we used clouds filter and then difference clouds a few times till it looked like this (ctrl-f to repeat action difference clouds a few times)

After that went to image>adjustments>gradient map and played around with colours till go the result that I liked

Corrugated iron

For this demo we took a new canvas of 900x900 unlocked a layer and used rectangular marquee tool and selected area.

Then used reflected gradient tool with light grey and black colours selected.

The next step was to define pattern with edit>define pattern. Then selected the whole canvas with rectangular selection tool and used fill with options selected use: pattern and in custom pattern select pattern that you have defined.

after you get this you can create new layers add rust on top or create some other imperfections to make this look more realistic.

some experimenting

 actual photos of corrugated iron