Minion block tips?

So, I was playing as Diana(Go figure.) in a duo/dynamic queue with a friend that I often play with. I attempted to kill my low health lane opponent who was standing right behind their caster wave. I hit them with my combo, landing my Q to reset my R as I dove, and immediately R'd again - Leaving my opponent with about 15 health - One AA from dead, yay!

Now the problem - My R puts me on the other side of them, the second one put me into the minion wave - RIGHT next to my enemy, yet he took one step back and it was over. I couldn't move toward him without running several steps to the side to skirt around the three caster minions. He proceeded to walk away and survive. The friend I commonly play with had seen it happen, and said "Man, at least once a day you have a problem with minion block" and I realized that he's right, it happens to me CONSTANTLY this season. I'm sure part of it has to do with the fact that my E pulls everything toward me, and thereby surrounds me with minions if used in a wave.. But I can't really help that sometimes.

Does anyone have any tips for dealing with the minion block? It'd be silly to run Phantom Dancer or Ghost on Diana just to deal with it, but it's been giving me so many problems lately. Has anyone discovered any smaller collision zones on one side of the minions or something maybe, to where I can focus on something like "Always go to the right of casters, the collision box for them is slightly smaller there" or SOMETHING? It's just been so much worse for me this season than ever before.