When you’re jelqing, try to keep your erection level high enough that the pressure doesn’t just start to build when you are half way up the stroke or you could exacerbate the baseball bat effect. If you keep it 75% + (not more than 85% though) and kegel just before the stroke, so pressure starts at the start of the stroke, it should stop that happening. Jelqing too hard and too flaccid (say 40%) is not good for baseball bat shapes. I found just manual stretching filled out the base quite a bit. Hanging did even more, and pumping gave temporary base gains that almost turned it into a tree-trunk shape.
I’d start with just the stretching (i.e. not hanging or pumping yet, as iamaru said) and emphasise it over the jelqing to begin with. Do keep some jelqing in the routine though.
Forte est vinum fortior est rex fortiores sunt mulieres super omnia vincit veritas: "Wine is strong, a king is stronger, women are stronger still, but truth conquers all" (1 Esdras, chapters 3 & 4)