The “free” air and mind runes are given by the magic tutor, east of lumbridge castle. She gives you 30 air and 30 mind runes every time you use the option “claim from”. You can only do this once every 30 minutes however. You can work around this though, by creating multiple accounts. 10-20 accounts would be a good number.
After getting runes from her on one account, go to the other accounts and do it. Eventually, you'll have 30 air and mind runes on every account. If you have air and mind runes on you, she won't give you any. You can solve this problem by dropping your runes away from her and asking for more. Make sure not to drop runes right next to her, because she can detect them and tell you that you dropped them.
A suggested place to drop your runes would be in the general store, far away that she can't see them, but close enough that they won't appear so that other people can take them.
This method is fool-proof and it works. I have 2.3 million airs and minds right now!!! Air runes can sell for 20 gold each, so I have about 46 million gold!!!
