in areas with long daylight hours, jujus don’t really need pruning, since the flowering(fruiting) stems fall off in autumn, and old laterals that get shaded by laterals higher up will regress.
but as @k8tpayaso mentioned, there’s not much pruning methods needed in her orchard since her trees are grown out in the open, with no trees/walls or structures nearby which may block sunlight.
if you’re growing your jujus near tall structures, especially in northerly latitudes where overall(annual) daylight hours are so much shorter, it is best to encourage your juju to get tall as it can be, at least to be taller than nearby trees, or at least taller than the shadows being cast on the juju by nearby trees/structures.
it may take long for this to be attained if planting near structures/trees, so best to find the sunniest spot in your orchard. Once you’ve estimated the tree to have maxed out its full exposure to sunlight(or won’t get substantially more sunlight with additional height), but still not fruitful, you should be on the lookout every spring for upright growth, removing them as they develop, and just let the deciduous flowering stems grow. Upright growth is more stem than leaf(compared to flowering stems, which have very thin stems and plenty of leaves), so upright growth is a huge drain on the food supply coming from the roots during spring. Important to note that growth in early spring is mostly an initial net loss of sugars for the plants, especially when producing thick and long non-photosynthetic stems.
there are youtube video posted by chinese farmers and korean farmers promptly pinching upright growth buds. At any rate, upright growth is only useful(for attaining height) initially when there are too many tall structures near your tree which casts shadows over it.
getting rid of upright stems thickens the lateral stems(as well as prolong the laterals’ lives), which bear fruiting spurs(from which the deciduous flowering shoots develop from ). When grown out in the open, you could train your jujus into bonsai’s by getting rid of all upright stems, and just let the laterals do their thing, i believe i posted a link somewhere at growingfruit about jujus being grown like tomatoes, bearing fruits at less than 3 feet tall with very thick and old laterals.
one more note, fruiting spurs are stems, but very slow growing with short internodes, and each year of growth increases the number of nodes from which the deciduous flowering shoots will develop from.
below is an old contorted lateral which bears at least two flowering shoots from each node/fruiting spur(usually only one and somewhat short and spindly on its first year), which results in shaggy, weeping appearance
below is a shaggy lateral which also developed upright growth. Upright growth is seen here as a tan and freckled growth with sparse laterals. Being young, there are not many nodes on the still nascent/microscopic fruiting spurs
Fruits may be borne on the laterals of this young vertical stem, but not as much as the shaggy lateral stem it bolted from, which evidently has denser production of fruitlets.
so as not to digress too far from main topics, below are pics sugarcane fruitlets and honeyjar fruitlets, respectively. SC and HJ are two of the earliest jujus we know of. Contorted’s and li’s are also early