Bump!
Mining: For now, camp out in the Mining guild, gathering mithril ore. It'll be slow, but you'll make some cash, and you're looking at about 4-5 hours of work. You could also do granite, if you're wanting it done faster.
Crafting: Glassblowing seems to be the cheapest method, at the moment. Though, to be fair, dragonhide will be much quicker, but also a bit more pricey. If you want to make good money, do bowstring, but you're looking at over 7k of them to do, easy.
Agility: Unfortunately, this is a grind. Go to wilderness. Use your silverhawks, if you have them, but just be prepared to knock this one out. Don't use Ape course.
Herb: Combat potions are cheap, or even super attacks would be a great way to train, but this is money as well. Sorry, man.
Either way, you're going to need some cash, so be prepared to spend, with a bit of grinding for Agility/Herblore.
Good luck on your goals!
These are Beautiful Times.