Distributing your ap points can save you tons of  maple stroy mesos. For warriors and mages, putting points into hp recov/mp recov will save you money from buying pots. Saving points for special attacks (lucky 7, magic claw, double arrow, power slash, etc) also will allow you to spend less pots (example: lvl 10 lucky 7 wastes 8 mp but lvl 11 wastes 11 mp and you only get a lil more damage out of it, so save the next 10 points and put them at the end).

Another way to save money is to buy cheaper equipments. For example, a sin with 4 subis and 2 wolbis wants to get better stars to deal more damage. He goes and buy 4 mokbis and 2 icicles. He deals more damage after the stars but spend more than a million mesos. Why not just stick to your subis and wolbis? At your current level, str/int/luk/dex/matk/watk will not increase your damage to the point you can 2 hit somthing that is 5 levels higher than you. So why bother wasting money on that? Remember, don't waste money IS saving money.

How to gain money
Gaining money could be fun and enjoyable. There are three ways to gain money: getting drops, doing quests, and buying/trading items.

Getting drops: Dropping rate is random. There are no tricks to this. This is based on your luck. If you are lucky, you get more drops. If you are unlucky...too bad for you. I can do nothing about it. If you get less drops than others, don't complain or whine. You are simply unlucky. Besides, getting drops is not the only way to make money. However, you can get better drops than others from different types of monsters that will improve your mesos gain per drop.

Doing Quests: Quests are fun to do (for some people at least). I love doing quests. It is fun and you get good mesos/items out of it. Here are some quests that give you decent  maple stroy mesos /items/exp.
I'm Bored
Teo's reminiscence
Nella and Kerning City Citizens Request #1
Nella and Kerning City Citizens Request #2
Pia and the Blue Mushroom
Shumi's Lost CoinCamila's Gem
Sabitrama and the Diet Medicine
Mystery of Niora Hospital
Jane and the Wild Boar
Shumi's Lost Bundle of Money
Nemi's Dilemma
Toy Soldier's Walnut

Buying/Trading Items: A very important skill that everyone should learn. This could make you as rich as a lvl 70 person if you do it right. First you buy an item that is cheap, then you sell it for high! It is that easy! But this will waste most of your time gathering information on the average price of items, sellers, and buyers. This is not highly recommended if you are still at a low level (due to low amount of  maple stroy mesos).