Most of things i write here are shamelessly ripped off from other media.
1) Vampires must consume blood on a fairly regular basis - it is a great and unknown mystery why, but every day a vampire goes without feeding his body somehow metabolizes some of sanguine liquid that it has inside it instead to uphold their conditional immortality. In average, considering that the vampire has not expended his effort and his blood to power his mystical abilities or for anything other than upholding their immortality, he must consume roughly three gallons or ten litres of human blood in about half a month, meaning that he must completely drain one adult human every week in order to function on the peak of his usual capabilities. The longer a vampire goes without feeding, the more corpse-like, irritable and animalistic he becomes, lashing out at friend and foe alike. A vampire starved for blood dries up, withers, becomes immobile and begins to hibernate until somehow, sometime fresh blood is spilled in his vicinity or comes into contact with him. At that point the living corpse rises again and uses whatever strength he has left to hunt down and devour all sanguine liquid he is able to find in a mindless hungerous frenzy in order to return to the normal condition. As opposed to this unholy thirst, werewolves must merely consume thrice the food a normal human of their weight eats in a day in order to power the metabolism of their immensely powerful bodies.

2) An aspen stake or spike driven through the heart does not kill but immediately paralyzes a vampire similarily to how he becomes dormant if starved, the only difference being that while staked the vampire is completely aware of everything around him - this is one of the greatest banes for the bloodsuckers. An accurately placed arrow or bolt or even a single tiny chip of asp lodged into the vampire's shrivelled heart is enough to spell his doom. For this reason many vampires often wear some form of armor on their upper bodies, especially thick against the heart. A vampire left immobile under the sun will eventually be burned to death in this weakened state.
Werewolves on the other hand, have a different bane, which is silver. Wounds made with silver weapons heal much, much slower than any other and they always leave ugly scars that can't ever be removed even if they don't impact the functionality. This is because of an ancient oath werewolves of yore had once struck with the spirit of Silver in the times when skies told us fables and stones wept honey - it would've lent them great strength in battle and shining fur that'd deflect any strike and they had to only look to that Silver would rest peacefully in the bowels of earth forever and ever. Naturally, when the first human pickaxe struck into the metal, Silver became enraged and cursed the shapeshifters for violating their promise and swore to bring them doom and suffering.

3) Both vampires and shapeshifters share another crippling weakness - weakness for fire. With them both being much closer to animals than simple mortals, the primal fear of open flame long lost in humans is reawakened in their minds. It is a phenomena known as Fire Frenzy among werevoles and Peur Rouge in the vampire community - an irrational and infinitely horrible fear of fire in almost any form. Smoking is considered quite a daring display of one's gut and courage - or, more often, pointless bragging.

4) Werewolf condition is hereditary. There are dozens and dozens of bloodlines and clans, each with their own agenda and goals. Except for being born to be wild, there is one another way to become a shapechanger, considered amongst them to be sinful and blasphemous. A mortal willing to take this path must hunt down an adult werewolf, kill it without damaging the hide and skin it. Afterwards the hunter is sewn inside of the hide and thrown into a cauldron full of boiling wine made from the pulp of cocoa beans. After a whole hour of horrible heat and searing pain the cauldron explodes and reveals to the world a new skinwalker.

Vampires on the other hand can only be sired by other vampires. This is done by a vampire completely draining the chosen prey of blood and then feeding his own vampiric blood to the corpse. Most of the time the freshly undead person is also buried under eight feet of earth - if at the evening of next day the vampire manages to claw his way to the surface, he is considered strong and promising.