Goodwill

Send goodwill messengers to other clans to raise their trust. You can later consume trust to form alliances and negotiate for reinforcements.
Gold will be consumed every month for each emissary sent to a different clan, earning trust as a result.
Designate the amount of trust you need for a particular action, and then let the emissary automatically build trust each month.
Select Diplomacy > Goodwill from the command menu.

Ease of Raising Trust

The following factors will alter the ease of raising trust:

• Stance (Friendly > Cooperative > Normal > Untrusting > Hostile)
• The emissary officer's POL
• Any traits the emissary officer has that affect the change of trust
• The difference in prestige between the two clans
• Whether the target clan is your vassal