Ninjas were typically called shinobi and shurikens are not only pointy stars, but any object that the shinobi would throw.
To become a ninja, you first had to be a jack of all trades. Being a ninja isn't only about scouting, survival, poison, and explosives. To be a ninja one had to master the art of disguise. This ment needing alot of skills in different fields to enable complex and realistic disguises.
Being a ninja was also dangerous and passing on information was a must. If these messages were discovered, not only would they be compromised, but they would also alert the enemy of their plan. But a simple encryption would be cracked as long as it is intercepted. Thus the method they used was colored rice. By using a different assortment of colors and positioning, they could send all kinds of intricate messages. This method would also prove to be undecodable as the rice can be layered and even the orientation would play a huge factor.
Ninjas were able to read the time off a cat's eyes. [not sure why this would ever be practical as the cat eyes need light to adjust]
Ninjas liked to weaponize just about anything from hairpins to nails. All of their weapons were dipped in poison and hidden in common locations. An example would be the yatate (the equivalent of an traditional Japanese pencil case), or small container made of bamboo to hold ink and writing utensils.
Ninjas brought crickets on missions to help mask their footsteps. They would also wear casual clothing to blend in. Anything else would have been suspicious. To create the smoke bomb effect, they brought ash in eggshells.
The ninjas are actually the reason why they seem so mystical and powerful. They encouraged and helped spread unbelievable rumors to confuse enemies. This also made everyone fear the ninjas as they were a hidden, unknown, and mysterious factor.
All the ninjutsus (special ninja techniques) were only passed on within families to worthy children. Only by keeping their ninjustsu and secrets to themselves could they survive. Ninjutsu was the very lifeblood of a family as it contained all their collected experience through countless generations. By trusting none and staying neutral, ninjas were able to thrive. They could be hired for all kinds of purposes from guerrilla warfare to sabotage.