Runescape gold earnings from picking up Ashes will give you a sure rs gold earning.

 

Burning woods and picking up free ashes to make runescape gold

After burning logs, Ashes appears and can be collected. Aside from burning rs items logs Fire Spirits can also provide ashes and has a potential of giving out bonfire training as rewards. While members are able to use the ashes for their herblore training, while free players can only sell the rs items ashes for cheap rs gold.

Most of the free players were able to collect ashes in the playerauctions grand exchange. While buying with rs gold or cutting logs will also be useable to make your own fire to produce ashes.