Step One
Carry your axe over to the western border of Varrock and cut down every tree in sight. Deposit the logs, and start again, until you have 97 logs in your bank.
Step Two
Start cutting down oak trees, until you have 293 in your bank. Then, head over to Draynor Village.
Step Three
Cut 3858 willows, depositing them into your bank. Then, head north to Edgeville to cut yews.
Step Four
Yews sell for 350 gp in the Grand Exchange, so get rich! You just mastered the woodcutting skill in less than four hours!