Money making in Runescape

One option is to buy (on the GE) unstrung magic longbows or shortbows and buy or harvest flax, spin the flax, string the bows, and sell them back. This will only make you about 160 gold per bow.

If you want to use magic and you already have a lot of money, you can buy, enchant, and sell onyx amulets for about 800K gp per amulet. I am not sure what the trade volume on that is, so it could be difficult to buy and sell the amulets.

If you have Lunar Magic and you have completed dream mentor, you can buy mahogany logs, use the spell Plank Make, and sell back the planks for a profit of about 800 each.

Initial experimentation shows that the bonuses stack multiplicatively: When cutting ivy, which has a base experience of 332.5 experience per cut, just wearing hat and legs for lumberjack outfit gives 3.3 bonus experience per successful cut (about 101% experience). Wearing just the Sköll boots gives 332.5 bonus experience (200% experience as expected). Wearing all of those gives 339.1 experience (202% experience). The bonus from the boots combines with the bonus from the Seer's headband 2+ the same way (giving 220% experience total).

However, wearing the boots and using a sacred clay tool at the same time gives the same bonus as using either individually for a total of 200% experience. This also happens with the combination of the Hati gloves with sacred clay armor and weapon.

In addition, the boot/glove bonus experience does not stack with the bonus from the bonus experience weekend.