I simply want an admittedly wish-fulfillment, but what can I say, I LOVE when Twilight shows off her magic power scenario where Twilight is forced to really go all out with her magic (which is hard in a normal episode… I can think of a few scenarios where it wouldn’t be too egregious, I’ll probably edit this with a simple example) and Starlight is shocked at the level of magic power Twilight actually possesses and a (personally) necessary scene where she wonders to herself how the heck did she manage to hold her own against her , to the point she, for the first (real) time, is wary of her own use of magic because it could really hurt other ponies if she loses control. Then Twilight points out in some ways, Starlight already was hurting other ponies even when she didn’t think she was losing control. Twilight reassures her that she’s come a long way from the pony who would snatch up cutie marks on a whim.
When Starlight asks Twilight how she manages to not hurt ponies with her magic, Twilight teaches her how to restrain herself and relaxation techniques which probably Twilight should’ve taught her a long time ago which she learned from her sister-in-law Cadance, and from Zecora. They can even visit Zecora and practice some meditation ala from Magic Duel.