How do you play your DK(s)?

Put rotation in a macro and mash button?

Actually watch for rune cooldowns and use appropriate strikes?

Any other options?

Pull with one to a certain area where you can bash the mob within the alts range. Melee turret ftw.

Death grip rotation on the 4 followers plants the mob directly in melee range for everyone. Chains of ice are cast from another alt and strangulate if one of them have it available, if not I mind freeze casters with the main.

4-5 icy touch hit next depending on if I had to mind freeze or not.

Obliterate kills any regular mob that survived the first hit, on elites I use death strike first. That 3 round spell rotation will kill pretty much anything at level fairly fast and keep everyone topped off on health. I'm working on getting better control over their attack rotation but it hasn't been necessary yet.

My DK is my tank. I mostly mash 1 button for damage/tanking. I use an extra button for various abilities (death grip, dnd, dark command, anti magic shell, anti magic zone, unholy blight, bone shield, icebound fortitude - all keybound to different keys), but 95% of using my DK is mashing a single key.

Not sure if specs matter, but mine are mostly blood (down to vampiric blood), frost to annihlation and rest in unholy.
It depends on number of mobs and difficulty of mobs. You can scale down or go farther down as necessary.

Too easy mob (-2 levels), just icy touch(x5) for melee or death grip (with an alt, so mob is in range of everyone) if ranged and auto attack.

Normal (same level), icy touch(x5), blood strike (just for DPS and use runes so you get runic power). Then alternate so next mob is plague strike and maybe blood strike. Then third mob is like icy and plague only. You can make up any rotation, I just like to use different ones so I use mostly all my runes.

Medium hard (+3 levels or -2 levels elites). Pick biggest mob first, since I need it to have a lot of HP so it doesnt die fast. Icy touch, plague strike, pestilance, blood boil (or blood strike--up to you). I just try to burn my blood runes, cause they are helping (DOTs ticking on mobs while I am busy killing one) and make the blade barrier (no blood runes makes parry go up) helps. Then when really hurt or on second mob (diseases last longer due to unholy talent--like 2-3 tier), death strike to get health back. Usually mob is dead. Can just wing it after that.

Hard (+6 levels or +2 level elites). Again, pick biggest (most health, doesnt die so fast). If you don't like a mob (mean caster, ranged, etc), just pick it first since it will probably still have enough health since it is higher level and it will probably die pretty fast after you get your diseases spread. Icy touch, plague strike, pestilance, blood boil (or blood strike if single mob only, otherwise boil--want healing from damage--blood aura). If you can wait for 2nd mob, just auto attack, if not, death coil 1 to 2 times, and then death strike 2nd mob. I like to run with 100% runic power normally, it makes death strikes HUGE (glyph) and gives me a way to do anthing I need if poop hits the fan.

Basically I don't watch runes except for blood since I deliberatly burn them at the start. The others I get a death rune (talent) for anyway with my death strikes, so I don't worry about them. I have never really had a time that I didn't have enough frost or unholy runes. It probably depends on spec though.

Hope that helps.

This is the spec I'm using:
http://www.wowhead.com/?talent=j0EMcZ0xZfg0hhckgcoMckut

Unholy Tank, but also puts out some decent DPS.

I keep my abilities fairly spread out, the only real macro I use for the DK is a Scourge Strike/Death Strike macro.
#showspellbyname Scourge Strike
/startattack
/cast Blood Fury
/cast [nomod] Scourge Strike
/cast [mod] Death Strike

Since I do tank/dps in raids I like to have my abilities spread out where I can get to anything/everything when I need to. My pull starts with Icy Touch (unless there's casters, then it's Death Grip/Strangulate). When mobs get in range, I hit them with Plague Strike followed by Scourge Strike spam (same button as lightning bolt macros on my Shamans). SS is great, because it generates Runic Power. Depending on the size of the pull, you should start spreading dots Pestilence, then Blood Boil, this should ensure you have aggro. If you've got a lot of mobs, you can do DND and Unholy Blight. Generally though, I don't bother. Just Pestilence my dots, and SS/Coil it till it's dead.