I’ve chosen an archangel but I can’t imagine the evocation keys, what do I do? I don’t know what the smell of metal is like and I don’t know what the author means by hard ground? What to do if you don’t know how to imagine them ?
Use your memory.
You have experienced hard ground in your life so you know exactly what it is, and how it differs from soft ground (it’s basically any ground you don’t sink into when you walk on it).
As for the smell of metal. Have you ever held some coins in your hand for several minutes and then noticed an odour on your fingers? That is the smell of metal, released by your body heat.
So it doesn’t need to be ‘hot’ metal?
You just said “the smell of metal” so that means any smell of metal will do.
Oh sorry my bad, it said hot metal, I’ll check and see if iron will do
You could grab something metal and sniff it. Then use your memory to recall the smell.
I think ideally something old and made of iron.
A well used cast iron skillet for example. Get it wet and smell the scent that comes off it.