FIRST OFF: Buy preist bottom and staff, unequip all items and equip those 2 items, 2nd objective, go to World 1 or 3 (recommended for extreme Money-making). Find a High-level Scaper and follow, then use the lines " i got pked by Zezima phree gp pl0x", or "my Runescape gf had a baby and i need 5k plz I need". Using these skills of Mastery will earn you merit and money.
Option 2: Location to start: Varrock or Lumbridge World 1 or 3, dress in snazzy clothes because your going to impress some ladies, go and say "looking for gf/bf 555" once you picked up your lucky date take him/her to a secluded area and get to know the person, once you think you have succeeded in that area ask him/her to marry you and that they need to buy a diamond ring ( BIG MONEY ALERT). If you made it this far, arrange a small Marrage in the Lumbridge or Varrock Church and have a local Player to be your preacher to marry you both. Once him/her gives you the ring, quickly (important) LOG-OUT and world hop and sell the ring and Kazam, there is 3000 gp all yours to spend.
Repeat if needed.
Option 3: Stand under Varrock's West bank 3gp spawn in the basement of the bank (every 1 minute it spawns) now be extremely cautious you may have competion from local newbies.