You can always go crazy and make an actual tree that drops apricorns from it's leaves.
As for making one in replica of Generation 3's... You can just refer to Omega Ruby and Alpha Sapphire.
Oh and I think another cool feature you could add to the trees (they should really be called bushes) would be to add like a shaders compatibility, or just have them actually sway randomly a bit like there is a breeze blowing. Probably won't happen, but it's a nice thought, and I don't think animating that would be too hard.
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