I'm often asked about adding fields to the lead form so that when you convert the lead it will move the new fields to the new record ( account, contact, opportunity). While it's a very straight forward change, it had eluded me for sometime.
To custom the lead conversion, you need to change the mapping for the respective relationships.
a) Add the attribute to both entities & publish (if it’s a picklist, make sure you add the same values to both entities)
b) Add to the entity forms as desired & publish.
c) Go to Lead customization and open 1:N Relationships in the side nav.
a. Open account_originating_lead and select Mappings in the left nav
b. Add a new mapping for the attribute
Be sure to use the appropriate relationship
( contact_originating_lead, opportunity_originating_lead )