Making money with woodcutting.

Woodcutting level 1.
Chop regular trees.  They sell for around 37 coins each.  Makes about 10k-20k an hour depending on your woodcutting level.

Woodcutting level 5.
Oak trees logs sell for around 39 coins each.  Makes about 15k per hour.

Woodcutting level 60.
Chop yew trees.  They are normally crowded so i would suggest going to a very unpopulated world.  The best place to cut yews is at edgevill.  As it is very close to a bank.  They sell for around 457 coins each.  Takes very long to cut until you reach level 70 woodcutting.