One way of smithing is to buy loads of ore and nats, head into the mining guild and mine coal while superheating. If this is done with mithril you pay around 600 gp per bar, ( ore and nat ), and can then smith mithril platebodies which you can then alch for around 3100 gp. So that owuld be around 2100 gp profit per bar. This process is much the same with adamant except it requires a significantly higher smithing level. You will make a large profit superheating adamant though. I'm considering superheating for a while.. Obviously with adamant you get the 100 exp per smithed/smelted bar, which also takes 6 coal, (300 mining exp) and a superheat and high alch, I'll have to check the exp for those. I think it's possible to find people who'll do the superheating for you if you pay them 1.5k or so per bar, you won't get any mining exp but the smithing exp from platebodies is rather quick.