I do not know enough of the lore of the lands in Essos to know what are good trade goods for the area, but exotic goods come to mind. As the lands are close to the unknown east of magic and strange creatures, it would be fitting that trade goods such as tile and fine cloth are used. Anything that's expensive and rare to fine in Westoros would be wise, with a high demand for goods produced in the extreme north such as fur and high demand also for goods unable to be produced locally such as fish. The important thing to keep in mind with the trade in these areas is that the distance should effectively boost the price of foreign goods disproportionately compared to closely bordering cities in Westoros. A journey made in Westoros that takes but a single day should be profitable but not by much. A journey taking up to a week from Westoros to the East areas of Essos should be lucrative. Villages should receive a similar treatment, but with a very small amount of lucrative goods produced and perhaps even then produced only 50% or so of the time. I've effectively zero knowledge on the game mechanics under the hood regarding trade so I don't know if this is possible though.
One thing I've noticed on a new playthrough is that it isn't worth buying stone in the Quarry in Essos. The price should be much cheaper as the current value of 100 silver stags for one stone is for most places a net loss. A quarry of all places should be the cheapest place to buy the stone. It is balanced by stone being very heavy. During this playthrough a full load of iron and stone from the north to Bravvos and further, slowed by character to a speed of about 2.5 in daytime which is the cost of carrying it. I felt quite vulnerable to bandits and the like but thankfully was not caught.
A further recommendation I would make on Essos is that the spawning of bandits, raiders, dothraki and other miscreants be increased. The vast spaces without civilisation should give the land a Steppe theme, where its dangerous but very profitable on trade. Essos, especially the distant East is a land shrouded in mystery where few travel and the very real threat of Dragons or spooky creatures puts most off from venturing there. In the current version, its very empty with few parties of any kind seen across the land.