Your clan status goes up or down based on your relation with your clan as a whole. It is most often affected by how you treat other clan members, how you represent your clan in public, and what other clan members are saying about you. You only affect your clan prestige by your actions (Talking about yourself rarely ever helps, unless it's something your clan encourages). Other clanmates can affect your prestige by talking to clan elders. Likewise if you talk about other clanmates to elders you may affect their clan status. Although depending on how your clan deals with things, and their level of Clan Status, your word alone may not be enough.

Clan Status represents what your clan thinks of you, how many clanmates know about you, and how likely it would be for a clan member recognize you. It is reasonably easy to get the first few levels of clan prestige. The more you have, the harder it is to raise, as topping things you have done in the past becomes more and more difficult. But likewise it becomes harder for you to lose clan status to simple rumormongering.

Clan Status and Challenges:

Clan status can be used during non-discipline Social challenges only with members of your own clan for the purpose of bidding traits during a tie. You must announce that you are using your Clan Status, and how much of it you are using in addition to your traits. This is because clanmates are expected to respect those with more clan status. Like regular status, Clan Status may be ignored, but the person ignoring it will likely loose clan status for showing such disrespect.
Individual Clans:

Clan Prestige is handled differently within each clan. Status is gained and lost for a variety reasons.

Brujah:
Brujah clan prestige is bestowed more for attitude than specifics. The clan has at least a rough allegiance toward weakening authority and promoting anarchy, and acts which accomplish both or either win their performers status within the clan. Telling off a prince, disrupting a Ventrue deal (and living to tell about it), tweaking the Tremere or exposing a corrupt mortal politician for the fraud he is – all of these can win a Brujah points with her elders and peers. Unfortunately, the Brujah penchant for going after the high and mighty often turns the youngsters of the clan on their elders, which means that matters of prestige can get touchy. Rewarding a neonate for acts that subvert a Brujah elder is asking for trouble, but is also true to the spirit of the clan. Younger Brujah also have a habit of ignoring their elders’ pronouncements and setting their own pecking order. Such arrangements are usually based on questions of strength or numbers of adherents; Brujah tend to move in packs and follow charismatic leaders.

Brujah who are cast out of the clan can no longer call on clan mates for aid, and will get severally beaten if they show up at a rant.

Malkavians:
There’s no telling what might set a Malkavian above her fellows. Clan standing varies wildly from night to night, and the Malkavian everyone follows one night might be shunned the next. It only makes sense to the Malkavians, and not even to all of them, it seems. An approximate guideline is that anyone who does exceptional work to break down a shared perception of reality (say, by getting a prince to speak in tongues or a keeper of Elysium to hang a finger painting) often wins kudos from her peers, but otherwise the Malkavian system of prestige just seems to be a parody of the other clans’ approaches.

The Malkavian custom that has the highest profile and will earn them much clan status is the art of pranking, playing “jokes” on other Kindred so as to expand their perceptions.

Malkavians who are cast out of the clan are rare. They seem to be cut off from the other Malkavains some how. They often become depressed and suicidal, or maniacally work towards getting reaccepted into the clan.

Nosferatu:
Standing among the Nosferatu is based on utility and merit. Those who do exceptional work for the clan or who uncover particularly juicy tidbits of information (that can be later put to use; there’s not much use for theoretical knowledge down in the storm drains) get acclaim. Furthermore, since the Nosferatu are in continuous communication, a well-regarded vampire’s good press gets spread far and wide. Of course, the opposite is also true. A Nosferatu who fumbles an information exchange, gets a burrow violated or assaulted or who passes on false information to the rest of the clan finds his name turned to mud across the entire ShreckNET in a matter of hours.

Nosferatu who have been ostracized find themselves sleeping in the less favorable portions of the sewers (if such things exist), and cut off from almost all clan information sources.

Toreador:
Toreador gain standing within the clan for creating or discovering works of art. Particularly successful Balls, manipulations of other vampires or cutting remarks at Elysium also win a Toreador points with her peers. Substandard discoveries or performances, embarrassing moments and demonstrated failures in social settings, however, can earn a Toreador her clan’s unrelenting and eternal scorn.

Toreador with no clan status find themselves sitting in their haven instead of attending important social events.

Ventrue:
Clan prestige is acquired by the Ventrue as a by-product of success. Successful acquisitions, business maneuvers, political coups or other activities that benefit the clan or the sect are rewarded with prestige, though it is common practice for as many Ventrue as possible to try to grab some of the credit for any activity that goes well. Activities that circumvent the bounds of normal clan behavior are regarded cautiously; if they succeed without denting the fortunes of other Ventrue, the instigators are lavishly rewarded, but if they fail or hurt the clan, the punishment is severe. Ventrue who don’t behave themselves properly also risk losing standing in the clan, as do their sires and childer. Blood and breeding will tell, after all.

A Ventrue with no clan status not only finds himself cut off from clan resources; his Camarilla status and financial standing are often hit hard as well.

Tremere:
The Tremere grant prestige within the clan in slow, carefully measured doses. Following orders to successful conclusions, triumphs of thaumaturgical research, eliminations of the clan’s enemies and efforts that advance the clan’s agenda are all rewarded, albeit in small increments. Tremere who disobey orders, engage in failed experimentation or who weaken the clan drop in prestige dramatically. Considering the rigidly hierarchical nature of the Tremere and the intense competition for advancement within the clan structure, a single misstep can set a Tremere’s ambitions back literally centuries.

A Tremere with no clan status is either hiding very well or dead.

Gangrel:
Gangrel gain prestige from one another through Gangrel gatherings (called allthings), and by having word of their deeds and actions spread by other Gangrel. Prestige bestowed by members of other clans is generally worthless to the Gangrel, unless the outsider in question has done something to earn Gangrel respect.

Gangrel who lose their clan status are at least banned from all clan aid and gatherings, if not hunted down for their transgressions.