My DH, BIL and dad both work north-west WA. TBH I wouldn't even bother with a medical as all the companies have their own specific doctors they go to and will make you go through their own so you will only be wasting your money and time.

I hate to say it also (I know I must sound very negative here but it's not mean't to be), but most of the time it's not what you know it's who you know. And you should perhaps focus on one or two specific occupations as there are some tickets (like forklift licence etc) that you could get before applying. It's no use simply saying "I want to be employed in the mining industry" you need to really know what job you want and research that.