In winter, protect them from cold freezes below 20F and cold, drying winds. They are not very subject to dieback of the smaller twigs, but damaged branches or twigs may abort in winter. Fertilize in spring after the tree has leafed out and again in late summer or early fall. As their natural tendency is to shut down and cease growth in mid-summer, they require no food during this time. They have a habit of putting on some late growth just as temps are dipping into the freezing zone, so don't give a high nitrogen feed late in the season or you may lose some soft growth to the cold.
Chemical fertilizers are fine as are organic ones.
Calluses can be bulky so reduce wounds properly. For ramification, pinch new growth back to 2 leaves after 4 or 5 have formed during the spring. Guy-wires are quite useful with this species. Know that wired branches tend to lose vigor so don't pinch back growth too much on a wired branch. You can be ruthless in cutting back the roots.