* Cold brew. This is where you take coffee that's ground to a sea-salt consistency and steep it in room-temperature water for 8-12 hours. Then, you scoop out as many grounds as you can and filter the liquid through the medium of your choice. Paper filters work are my preference here, especially if you plan to keep the concentrate around for a while (you won't have particles that continue to steep).
* Cold brew with a twist. Cold brew has minimal acidity and tends to be, if potable, quite boring. You can add interest by beginning the brew with hot water. Pour just enough to wet the coffee--it's helpful to stir it a little--let it expand for 25-45 seconds, then hew to your brewing ratio by finishing with slightly cool water. After this, the water should be at room temperature and you follow the basics of cold brew described above.
* Hot iced coffee. Now we're talking. What I'd consider to be the more interesting flavors that coffee has to offer just aren't available when coffee is brewed with cool water. Cold brew is the brewing equivalent of a dark roast...it tends to homogenize coffees and mute acidity. The standard way to brew hot-iced is to brew at double strength and then immediately cool the coffee with ice. This is often done in a Chemex--use the same dose you'd normally use but only pour half the water you would. The remaining water is available as ice; the hot coffee drips onto the ice and is immediately cooled.
The problem here is that the coffee tends to be underextracted, which isn't a huge deal when you're drinking something cold. You can fine up the grind to compensate but it's just difficult if not impossible to get an optimal brew when you essentially use a double-dose of coffee, especially in a drip method. It's a little bit easier if you're using an immersion method--vacuum, Clever.
* Normal hot iced coffee. You can just brew as you normally would and dump everything over ice. But things'll usually be rather watery...
* Enter normal hot iced coffee that's not watery or offputtingly underextracted. This is what I usually do. I'll use a little bit more coffee than usual--maybe 25% more--and then immediately cool it using a Boston Shaker that's stuffed with ice. *Just enough* shakes to cool the coffee, then I'll pour.
The approaches above don't require any unusual equipment. If you find yourself really enjoying iced coffee, it may be worth considering a cold-brew dripper (the result approximates hot cold-brew) or a Hario v60 set (which makes a better version of the Boston Shaker method). Personally, when it's hot and I need to cool down, I really tone down my pickiness, a tendency that probably belies this little post here...