In my group we have a few extra skill tables that are available. We have the Animal Handling skills that are available to everyone that was introduced in town Cryer, Magic skills that are available to anyone capable of casting (some are magic or prayers only), and Leadership skills that are available to anyone that is the Leader or has their racial max for Ld e.g. a human with 9 Ld or a skaven with 7 Ld. Ld skills only affect models in the same warband as the owner of the skill. We also have a houserule that states animals are never considered to be within the Ld radius of the leader - for that you need the Animal Handling skills.
Chain of Command
If the Leader is not available for the battlefield (most likely because he is missing the game or OOA) you may nominate one model with Chain of Command on the battlefield to be the new Leader. For the duration of the game, this model is considered to be the leader unless another leader is nominated.
A warrior with Chain of Command skills may choose skills that are otherwise Leader Only, but note that they will not stack with other instances of the same skill.
If the warrior started the game with Leader then they are eligible for the Winning Leader xp.
A Leader with Chain of Command may nominate any model capable of earning xp to be Leader for any game he is forced to miss. This will last until the leader is again available for battle.
Deputy
A warrior with Deputy recognized as being able to speak with the voice of the leader in the leader's absence. A warrior with Deputy may extend his leadership stat to all those within 6" of him just as if he had the Leader skill.
A warrior with Deputy may choose skills that are otherwise Leader Only, but note that they will not stack with other instances of the same skill.
At the start of the turn, a Leader with Deputy may nominate any one model as a deputy. That model will be able to extend his leadership stat to all those within 6" of him just as if he had the Leader skill. Only one model may be nominated as deputy at any given time.
Fomenter of hatred(a) (Stolen from Rhoaran)
At the start of each battle warrior participates in, nominate one enemy hero. All henchman capable of gaining experience gain ‘Hatred’ towards that hero this battle.
Fomenter of hatred(b) (Leader only)
At the start of each battle warrior participates in, nominate one enemy warband. All henchman capable of gaining experience gain ‘Hatred’ towards that warband while within the Ld radius of the leader. This effect lasts until the leader is stunned or OOA.
Fomenter of hatred (c)
At the start of each battle warrior participates in, nominate one enemy warband and one henchman group capable of gaining experience. That group will gain ‘Hatred’ towards the nominated warband.
Fomenter of hatred (d) (Leader only)
At the start of each battle warrior participates in, nominate one enemy warband. All henchman capable of gaining experience gain ‘Hatred’ towards that warband for the first round of close combat.
Charismatic (Leader only)
Your warband limit is increased by 1. Does not stack with other instances of Charismatic, but if the leader with Charismatic is replaced by one who also has charismatic you will not have to reduce your warband size.
Hunch (Leader only)
You may deploy 0-3 xp earning models in any terrain feature that is not within 12" of an enemy model or within your opponent's deployment zone.
Inspiring Presence (Leader only)
Warriors within the Leader's Ld radius may reroll a failed fear test (excluding the leader). This skill may not be used if the Leader is kd/stunned.
Fearsome Presence (Leader only)
Enemy models inside the leader's Ld radius radius are at -1 to hit for their first round of combat. Models immune to fear are immune to this effect. This skill may not be used if the Leader is kd/stunned.
Fearsome challenge (Leader only)
Roll a D3. Enemy models charging models within the Leader's Ld radius must subtract the result from their charge range. Models immune to fear are immune to this effect. This skill may not be used if the Leader is engaged in close combat.
Decisive Charge (Leader only)
Once per game the leader and all models within his Ld radius will gain d3" to their charge range and Frenzy for one round. This skill may not be used if the Leader is kd/stunned.
Rallying Cry (Leader only)
Once per turn any model within the Ld radius of the leader (excluding the leader) may auto-pass a Ld test. This skill may not be used if the Leader is kd/stunned.
Encouraging Shout (Leader only)
Once per turn one model (except the leader) may reroll a missed hit. This skill may not be used if the Leader is kd/stunned.
Command Aura (Leader only)
The base range for your Ld radius is now equal to your Ld instead of 6". Skills and abilities that increase this will work as normal.