I haven't played played in awhile and years after that, the last one-shot prerelease tournament I participated in was Return to Ravnica's second set (Gatecrash?).
This year, for Christmas, friend from gradeschool and I each bought the other six packs and we played pack battles, a draft, and then constructed out the opened cards.
Was great time. I had two packs of Kaladesh, Amonket, and Ixalan.
I enjoyed the energy mechanic from Kaladesh, but I'm saddened by how it's apparently unfun in tournaments. I bet if there was a third set, it would have been balanced out. I imagine cards that kick if the opponent has energy, in the very least red spells that blow up the counters. In the limited capacity that I was exposed to it, it was refreshing and cool.
Pack battle: blindly shuffle in one of each land and then set aside basic lands in respective stacks. At the beginning of your upkeep, you may put a land from the supply on top of your library.