This is a guide recommended for runescape players with a woodcutting level of at least 40. It may not be the best way at first look but its my way.
Lvl 40
At this level I would recommend not going onto willows at yet. They are slow and tiring even at ten levels afterwards. Oaks are the best way to go. Log into the least crowded server you can find and go to Draynor Village Jail (South of Bank). There, go a little left and you'll see two Oaks. Just alternate when one is done. Bank and repeat. The bank is literally 5 seconds away. If this space is occupado go a little right beyond the fencing and there will also be two Oaks. Just keep going until level 50.
Lvl 50
Okay, now its time for willows, at last! Now, you're probably thinking go to Draynor and bank, right? We'll if you want fast exp. then, no. Go down to Rimmington (Where you start Witch's Potion) and go down to the coastline. Ta-da! Willows all around with almost nobody ever there. When you've got a full inventory just sell to the general store!
thnks