I just found something interesting about the early Ming. It appears from the Ming Shi-lu that the Ming founder at first just sent envoys to various tributary states to inform them of the founding of the new dynasty. Within the next couple of years, however, new envoys were sent out.
Envoys were sent to Annam, Korea and Champa to carry out sacrifices to the mountains and rivers of those countries. Previously, the Emperor had observed abstinence in various respects and had personally compiled the sacrificial text. On this day, the Emperor held an audience and provided the envoys with incense and silks. The incense was contained in gold boxes. The silks comprised one length of silk and two pennants of patterned fine silk. All were in the colours of the four directions (方色). The sacrificial tablets were personally signed by the Emperor with his Imperial name.
The Ming emperor was doing as much of the sacrifice as possible without leaving home, (with his envoys doing the rest) so that he was personally making the sacrifice and he was really the ruler in those places. I think this is new, and the impression I get is that the Ming were at least initially thinking about a much closer relationship with their tributary states, possibly under the influence of the Yuan example.
Have I been doing translations from the Ming Shi-lu in my spare time? No. Geoff Wade has been putting his translations of those parts of the Shi-lu dealing with Southeast Asia on-line. The search function works quite well and makes it a real research tool. It is a very cool resource, and much worth looking at.