Easy way to earn money on Pokemon Omega Ruby/Alpha Sapphire?

Earning Money:

You can use these to earn more money:

1. Amulet Coin* or Luck Incense** (Make your lead Pokemon hold them, they do not stack)
2. Prize Money O-Power***

You can make the best use of them by re-challenging:

• Trainers (Check the AreaNav's 'People' function to find them)
• The Elite Four (also unlocks other goodies)
• The Food Court in Mauville City.
• Secret Base Trainers (AreaNav 'Bases')

Saving Money:

Having more money is all well and good, but what about spending less as well?

• Use Bargain O-Power for discounts (half-price at level 3)
• Buy Balls in groups of 10 each, to get the bonus Premier Ball as well.
• Pickup Pokemon will occasionally find a Great or Ultra Ball, depending on their level.

Catching Pokemon

Now, onto the crux of the issue, catching Pokemon efficiently, so as to waste less Pokeballs:

• Use a Catcher Pokemon. Sleep + False Swipe will make a lot of Pokemon easy to catch, even with regular Pokeballs.
• Use Catching O-Power.
• Make use of Quick Balls and Timer Balls****.
  • Quick Balls have a greatly boosted catch rate if thrown as the first move. Good for Pokemon that tend to flee.
  • Timer Balls have a greatly boosted catch rate if the battle has gone for 10 turns or longer. Good for Pokemon that don't want to stay in their Pokeball/Stay asleep

_{* You get Amulet Coin from your Mum after the 5th Gym Badge.
** You can purchase Luck Incense in Slateport City
*** O-Powers are unlocked through the 'Strange Men' in Mauville Pokemon Center. Keep interacting with them, exiting and returning to the Center as they leave.
**** Quick and Timer Balls can be purchased from Fallabor and Rustboro Marts respectively.}

The best method is:

• Get a Level 100 Pokemon, (Preferably one with a ton of attack, I usually use Dragonite)
• Get an amulet coin
• Give Dragonite the Amulet Coin
• Max out the prize money O-Power
• Go to the elites with your Dragonite holding the amulet coin and before each battle use the maximum Prize Money O-Power, After each battle you will get a ton of money.

I normally go the the E4 for money, with an amulet coin, but I recently found out about the move Payday. All you need is a level 30 Mewoth and teach it payday. Every time you use payday you get 10x the level of the pokemon using payday. For example: If a level 30 mewoth uses payday once you will get 300 Pokedollars. And Every time you use Payday in one battle it will add up. So if a level 30 Mewoth uses payday 10 times in one battle, you would get 3000 poke dollars. Hope I helped!

Use Level 1 Prize Money O-Power with Amulet Coin or Luck Incense fighting the E4 and Champion--as long as your Pokémon are strong enough, you can do it multiple times (~48600 Poke).

Also, utilize people with all-Chansey secret bases. Chansey gives more prize money, and if you couple it with the above strategy, it should up your return.

I suggest looking for the same trainers that battle repeatedly. I used the Bargain O-Power to get myself some good bargains, and I suggest you do so unless you don't have the O-Power.

Battling the rich boys over and over usually helps. Although if you battle them too many times, they start to get tough. The elite four are BIG money earners, so take every chance you get to beat them. Luck incense and amulet coins always work, especially at the pokemon league. Mauville food court is a place I recommend, you meet lots of trainers there and they always earn you lots. Good luck!

Get a strong, maybe level 100 Pokémon. Give it the amulet coin and go to route 104, where there is both the lass and the rich boy. Activate prize money O-Power before each battle, and you can speed through the battle. I prefer my Aegislash using Sacred Sword, but any quick animation, powerful fighting type move works fine. At level one prize money, I could get 3 battles in. You do have to wait a bit for both the trainers to be ready and for the O-Power to charge. I got 17,640 per battle, and there's only 2 Pokémon per battle, so I guess it would be around 100k in under 10min, but like 5 min after that for the trainers to get ready, and a few more for the O-Power to charge.