My way to get NP is to forget all the things you usually do, just forget it. Place all your NP in the bank and leave it there.
Everyday spend about 3 hours or more, depending on how much game time you have, and play games (Games that are easy and pay out a lot; Swarm, Destruct-o-Match, Bumper Cars, Chia Bomber, Pterattack, and Cheat. Cheat, Pterattack, and swarm are really easy and get tons of NP, bout 1,000 or more each time you play, except with Cheat, cheat you get a lot of money depending on what level you are on).
Always take the time to play these games then go on to other games you like and have a good payout. Always remember to collect interest in the bank everyday before placing your NP into it.
Sell ALL items that you have that cannot be used to raise your pets abilities, status, and items that you use in the battledome.
Make sure to check the price rate of everybody else by using the Shop Wizard, Price your item lower than the other people. NOT 1 NP lower, but say if they are selling for 5,000 average, than you sell for 4,500 or 4,000. This will make your items sell quickly and you still get NP, sell even the items that everyone is selling for 1 NP, sell yours for 1 NP and if your user name starts with a number or a letter in the beginning of the alphabet, then it will sell fast. The shop should get you a good amount of NP.
Play games like the Wheel of Mediocrity, and other games like that, go to places that give items for free, so you can sell them; Giant Omelet, Healing Springs, Coltzan’s Shrine etc. Then place the free items in the shop to get more NP.
I’ve gotten about 10,000 NP a day from games alone and I’m not very good at them. From the items in the shop I’ve gotten about 5,000 every 2 days from selling free items and useless items I’ve bought in the past. Remember at the end of your day, place all your NP into the bank, and remember to change your account thingy (the thing that says Neopian student, Silver saver etc.) to what amount of NP you have. Refrain from taking your NP out until you have about 100,000 NP or so. (Getting this much shouldn’t take more than a week and a half.)