Research for Quest items!
Usually, When people do quests, The quests may be the same items used over and over again in many other quests. Visit the Snow Faerie, Esophagor, Kitchen Quests, etc.. You don't have to do the quests, Just accept and find out what the items they request. You'll have a general idea of what is being asked. The reason to do this is because most of the items that are asked for in quests are expensive in the markets. A real way to get some np!
Wait till the craze dies down.
Usually when new items are released, People buy them for LOTS of np and then have buyer's remorse when the craze dies down in a week or so. Lots of np are lost. If you want to get your hands on a new item that was released, WAIT till the craze dies out and the np WILL drop. This will save you a lot of np.
Never do Earth Faerie Quests.
When you're travelling through Neopets, Sometimes you will get a sudden random Faerie Quest asking for an item. If it's from the Earth Faerie, TURN DOWN THE QUEST! The only thing the Earth Faerie does is makes your pets "full". A lot of NP to waste if you do one for her.
Play Games you are good at.
There are all kinds of games like games that require thinking or games that are based on action and time. Find a game with a good np payout, that matches your preference, and enjoy!
When doing a quest, Limit your NP spending!
Limit your budget when it comes to these quests. If you're rich, then limit it to 5k. If you're poor, limit it to 2k or under. You'd be saving yourself a lot of frustration when the prize is worth a lot less than the item(s) you gave them.
Get a free daily omelette!
In Tyrannia, You can approach this MASSIVE OMELETTE and snatch a piece. Do this once a day! :) You can sell the omelettes in your store!
Visit the Healing Springs!
You can visit the Healing Springs every 30 to 45 minutes. The most wonderful thing is that you can heal your pets after a battle or the faeries could give you a free potion. She even heals your pets of any diseases that it may be suffering from. Visit several times every day. You'd be saving yourself a lot of np with the diseases and make np off the potions that she gives you if you decide to sell them.
