Now that we've had a bit of time with patch 4.0.1, hopefully you've settled in to a decent rotation and spec and have begun to feel your way around the new system. Now that you've done that, there's one more step to take: figuring out the best way to reforge and regem your gear. Reforging can be done through certain NPCs in major cities and is a process whereby you take one secondary stat (the ones in green text) and reforge part of it into another stat. This process can be very useful for getting rid of extra stats past the soft cap or just plain getting rid of stats that aren't important for your class or spec. You can't reforge a stat into another stat that's already on the item, but otherwise, your possibilities are endless.
Gemming remains more or less how it always has. The one big, new curveball we've been thrown is the fact that hit gems are now blue. This is probably overall a win for DPS death knights, as it gives us a few more options to aim for gear bonuses without handicapping ourselves as much.
To understand how, when and if to regem and reforge your gear, you'll need to understand stat weights. While it's still pretty early in the 4.0.1 game (and therefore, it's not completely clear what stat weights are for every spec), the death knight community has still done enough math that we're relatively certain of the general order. With that in mind, let's look at every spec and figure out the best ways to regem and reforge.