Taking a que from this WoW.com post, I’m just giving out some WoWhead links to some of the mentioned items there in the post and a few other things for your 4th/End of Midsummer Celebration.
WoW.Com is right, you’re going to need fireworks, whether Craftable or Vendored , and don’t forget the sparklers! But if you’re having smoke bombs, please keep the party outdoors (unless you’re in Dalaran).
Of course you can’t forget the Elune Stones!
Don’t pack up your juggling torches just yet, (please; no juggling near the fireworks)
With Ahune being blasted left and right, there’s no sense in letting those pockets of snow go to waste. Have a snowball fight.
And lets not forget the food; Gigantic Feasts, Small feasts, Dragonbreath Chili (just don’t invite your enemies!) And the brews; You’ve got the monthly June and July brews if the party is BYOB. And who doesn’t like a nice Slammer now and then?
Go big or go home!