I mined tin and copper from the Varrock southeast mine and walked all the way to the lumbrage furnace to smelt them into bars. I then walked back up to Varrock to smith the bars into the highest level item I could make. After that, I sold all the items I made to the general store in Varrock. I didn't think about banking my stuff back then, lol. It took me a while, but I made about 10k from all of that and got a few smithing levels. :D