The Hair
Kakashi's hair is grey. It could be grey for many reasons. First of all, it could be genetics and secondly, for those who are clean freaks, Kakashi may not be an avid bather so he may not have wash his hair often, so in other words his hair is white however it's grey because of very unsanitary reasons. Perhaps it would be better to assume that he has grey hair due to genetics. If Kabuto has grey hair and Jiraiya has white hair, then grey and white hair being a genetic trait in the Naruto world is a possible thing. Or, Kabuto is also born with white hair and ... nevermind. Kakashi also has 'big hair'. Compared to pictures of him of when he was younger and how he was today, it could be safe to presume that he doesn't get his hair cut frequently. (Sorry, the webmistress of this site is a clean freak, and also has a fascination with odd hairstyles)

Posture
Compared to the other Jounin instructors, with exception to Asuma, Kakashi would be considered rather laid back in not only personality, but in posture. Kakashi also usually has one of his hands in his pocket or is found reading another volume of Icha Icha Paradise.

Eyes
Kakashi only shows one eye. In non battle situations the visible eye either looks very indifferent, half asleep, or literally a "∩". Kakashi's left eye is usually covered by his Konoha forehead protector, however when moved from his eye there is a vertical scar, most likely a battle scar, and it the color of the iris is red at all times.

Mask
For unknown reasons, Kakashi is seen to be always covering half of his face giving him a mysterious look. This is the reason why in many Kakashi doujinshis, artists usually draws Kakashi without his mask. In a Naruto manga special, Naruto persuaded Sakura and Sasuke to accompany him on his quest to reveal Kakashi's face by treating him at Ichiraku Ramen. Sasuke declined however after Naruto suggesting that Kakashi may have fish lips or perhaps horse teeth, Sasuke eventually gave in. Unfortunately, as Kakashi was taking off his mask, Ino showed up and was excited to see Sasuke, as usual. After Sakura and Naruto yelled at her she finally got off Sasuke, however by that time Kakashi had already finished his meal. In conclusion, according to the expression of Teuchi, the Ramen shop's owner, and Ayame, a girl who is working at the ramen shop, Kakashi is apprently very good looking. Another instance in the manga where his students were interested in seeing what was underneath his mask would be when he fell unconscious after his first fight with Zabuza. This scene however is only shown in the manga where Sakura and Naruto were inching closer to him while he was resting however he suddenly woke up when they got too close.

Come Come Paradise
When the time is right, Kakashi will take out his beloved book and indulge in it. "Come Come Paradise" was first seen while Naruto was attempting to fight Kakashi during the Genin exam. Kakashi also owns, other books such as "Come Come Violent" and "Make out Violence". Unbeknownst to Kakashi, the author of his favorite books happen to be one of the Legendary Sannin, Jiraiya. Luckily, for Kakashi, "Come Come Paradise: Vol.2" is currently being written.

Forehead Protector
Since Kakashi is a Konoha ninja, he wears a konoha forehead protector which has a leaf like image on the metal area. Kakashi's forehead protector is usually slanted to cover his left eye, his Sharingan eye.

Clothing
Because of the green flack jacket which Kakashi wears, it's hard to tell whether his clothing is either a shirt and pants or a jump suit. His clothing is loose fitting and the top portion of his clothes also make up his mask.

Flack Jacket
a green vest worn by most of the ninjas of Konoha. There is a Konoha Logo on the back of the vest, and on the front of the vest is where the scroll pouches are located.

Gloves
The gloves Kakashi wears are open at the fingers and has a metal plate to protect the top of his hand. Kakashi first demonstrated this during the first fight between him and Zabuza.

Back Pouch
The back pouch situated on the left side of his body usually holds a book and kunais.

Shuriken Holster
Found on his right leg, situated inbetween the white cloth that wraps his leg. Perhaps his right leg muscle is easily strained?

Footwear
Kakashi's shoes are shoes which most other ninjas also wear. It is open in the toe area and at the back of the foot. Above the shoe is additional cloth which Kakashi has tied his ankle with.

Scarf
In the Naruto movie, since the story is situated in a colder region in the Naruto series, while his students wear capes, Kakashi wears a yellow scarf.

Mask
During missions, all ANBU members wear animal masks to hide their identity from others including those from Konoha. At times, some ANBU members may remove their masks when their mission is complete.

Clothing
Kakashi's ANBU clothing is tight fitting and is sleeveless.

Flack Jacket
White armour like vests which are attached by two shoulder straps are worn by all ANBU members. Compared to the vests non ANBU ninjas wears, there appears to be no scroll pouch.

Gloves
Kakashi's ANBU gloves are identical to his normal ninja gloves but without it being open at the fingers. The length of the glove is much longer that it goes half way up to his shoulders. Also, the metal protector on the top part of the glove is also situated at the same place as his regular ninja gloves. Attached around Kakashi's arms are long elbow guards.

Footwear
Identical to normal ninja footwear, however this pair of shoes are taller so that it is able to wrap around Kakashi's legs. The back of the shoe isn't open, however the front is.

Scarf
In the Naruto movie, since the story is situated in a colder region in the Naruto series, during a flashback of Kakashi's past while he was part of ANBU, he also wore a dark colored scarf.

Weapon
All ANBU members carry a katana around, Kakashi is no different.

Tattoo
On all members of ANBU, there is a noticable tattoo on their left arm.

Formal Attire
Kakashi was first seen in a formal outfit which not only him but all the other male ninjas of Konoha wear during the Third Hokage's funeral. The outfit is a two part piece which is black in color however the lining is a lighter color. It has a open neck area, and in Kakashi's case he wears something under it so so that he could mask his face.

Casual Ninja Clothing
The casual Kakashi look. Identical to his normal ninja attire but without the vest.

At First Glance
Compared to when he was younger, Kakashi didn't change much in looks. It's just the questions of where he got his Sharingan and how he got his scar being the only differences between the two. Continueing the "big hair" rant, you may notice that the younger Kakashi has tamed hair. The younger Kakashi also leaves a chunk of hair under his forehead protector. Perhaps he thought it looked suave. Kids are like that..

Clothing
When Kakashi was younger, he wore a simple blue suit with two straps running across his chest making an "X". It also has shoulder padding on both sides. Like the older Kakashi, when he was younger he also covered his face with a mask.