His civil reforms include the abolition of the system of prepaying taxes which had weighed heavily upon the wealthier proprietors, the elevation of the serfs into a class of free tenants, the remodelling of family and of maritime law.
Depending in how well you know the couple, a great gift could be in prepaying a bill or service you know they will need when they start their new life together.
For example, if your friend is getting married and you know they'll be getting DSL service from a specific company, you could find out about prepaying their first two months of service as your wedding gift to them.