You can add body by increasing the fruit content at the beginning or choosing to use an all fruit/all juice approach.
You can add body in primary with raisins or bananas.
You can use chopped raisins in stabilized wine in secondary but they may change the flavor for better or worse.
You can add glycerin to the wine to promote body, prior to bottling. Glycerine can impart a sweet taste and/or heighten the sweetening effect of sugar.
You can promote body by adding sugar, but it will also sweeten the wine.
Interesting on the black cherry. Every one I have had, including my own experiment, turned out to taste like cough syrup.