Select trees that match the conditions of your site. A tree that needs good drainage and full sun will struggle in a wet, shady place. Branches should be spaced around the trunk, with wide angles between the trunk and with 12 to 18 inches vertically between the main branches.
Branches growing from the same point on the trunk are more likely to split off in later years.
Such is the case with ornamental pears, which are also prone to narrow crotches. Dig a small hole 15 to 20 inches deep. Fill it with water. After it drains, fill it again. If water remains in the hole the next day, the site will be too wet in years with above-normal rainfall.