For the last week we have been making hundreds (for my dad thousands) of Law runes. The current price on the grand exchange is nice for the runes, but, there is a better way of making even more money. I go to my dad's house when he is on and we make teletabs. The fastest way is have several bracelets of clay. They allow us to mine 'soft clay' without the extra step of adding water later. We then craft teletabs at his house using the mahogany eagle lectern. I have made over 400k making house teletabs as they sell quickly (usually within one hour). If you have the construction level to make a study with a lectern it is a great way to quickly make a lot of GP within several hours.
For the law runes I don't have the level (yet) to make the runes, but, with my dad I can request his assistance at the law altar in Entrana. If you don't have a friend you can try world 66 or 99 as there are usually at least one person there who will give you an assist making law runes. The only thing is that they get the experience points and not you, but, for making money fast that is a fair trade.
The bonus is now I have enough GP to buy my dragon axe so I can now work on getting my wood cutting levels up even faster. I cut the Yew trees, sell them and buy maples so I can then burn them for getting to level 99 firemaking.