The easiest way to earn neopoints is to restock. If you have a fast internet and computer buying rare and expensive items from the neopets shops cheap and selling them at a high price can earn any neopian millions. The best shops to restock from are the BOOK SHOP and the MAGIC SHOP. Restocking takes practicing and skills. Don't forget that you will not be the only one trying to get an item so try and haggle as fast as you can. Remember to check the shop wizard for the price you should sell the item you buy. If you want to sell the item fast price it lower than the lowest price on the shop wizard.
Another easy ways to earn neopoints is to do dailys. Everyday, go to COLZTAN'S SHRINE, FRUIT MACHINE, THE WHEEL OF EXCITEMENT, and TOMBOLA. Also, remember to buy scratchcards whenever possible. If you want to be safe you should sell the scratchcards to earn some np. If you want to take a risk, scratch the scratchcard. Don't forget to visit the healing springs when your pet is sick instead of buying the medicine. The water faerie can heal your pet and save you neopoints.
GAMES can earn you many neopoints everyday too. Play as many games as you can everyday and your neopoints will rise. Don't forget that you can only send game scores 3 times everyday.