My Build - http://us.battle.net/d3/en/calculator/monk#WYgXRh!ZXd!ZYaZYa
This build's focus is damage mitigation because I usually play with at least 1 friend. I have done soloing with this build before and it works, it just take longer to kill stuff.
Crippling wave (concussion) - 20% slower attacks, 20% damage decrease, 30% snare, and cleaves. There is simply no better spirit generation for damage mitigation
Blinding flash (searing light) - 3 second crowd control in a 20 yard radius, at a cost of only 10 spirit, you simply can't give this skill up. I use searing light to give myself some extra mitigation against hard hitting elites. You can also use it to interrupt some enemy's charge-up attacks or even use it to break free from being surrounded.
Serenity (peaceful repose) - 3 second damage + crowd control immunity. One of the best monk survival skills out there. The attached heal increases survivability.
Breath of Heaven (circle of life) - a heal that can heal yourself as well as an ally, very useful especially for the more fragile teammates. You could replace the rune, however this build's focus is on survival/mitigation so the other useful rune in this case is penitent flame, which attaches a fear to the heal. (Which I find very annoying because it is much easier to deal with enemies that are tightly grouped up)
Inner Sanctuary (circle of protection) - a 5 second small area that when placed bounces/fears all non-yellow/purple/boss enemies away and prevents them from passing through. This skill is largely useful for its ability to block a path, allowing teammates and most of the time yourself to deal damage to enemies while out-ranging them. To use it effectively, search for a chokepoint like narrow valleys/doorways and drop the sanctuary down. Move back a 1-2 yards and shift+attack will let you out range most enemies giving you a 5 second window of free dps. You can also use this as an emergency to bounce away all enemies when you find yourself surrounded and buying time for your retreat. The circle of protection lets you tank some elite mobs that cannot be bounced away with an extra 35% mitigation. I don't use safe haven because it requires that I stand in the sanctuary for full duration for a small 7.5k-ish heal, not very useful when I am on the run half the time. The only other useful rune is consecration, giving you an extra 2 seconds.
Mantra of Evasion (hard target) - can't really say no to 15% dodge with virtually 100% uptime. This can be activated to boost the dodge rate by an additional 15%, which is useful for bridging between the other cooldowns. I use hard target as my rune, which roughly gives me 5% damage mitigation over divine protection. I think both are good, but I prefer a more consistent 5% reduction.
Resolve - enemies I hit deal 25% less damage, and I hit everything around me with crippling wave.
Seize the Initiative - 1000+ armor depending on gear, self-explanatory
The Guardian's Path - dual wield for 15% more dodge. Some may ask me "Why not use a shield?" and my answer has been I have never found a shield that can give me 15% damage mitigation. If I find one, sure I'll switch that up for Beacon of Ytar, which is the next best candidate in terms of survival, allowing you to bridge defensive cooldowns more easily.
My Strategy - I use the word tank very loosely. Given a choice, I will never stand still to take the blunt of the damage. I take advantage of the terrain such as chokepoints where I can drop inner sanctuary to halt enemy advances while out-ranging them with my crippling wave. In short, the best way to mitigate damage is to not let your enemy attack you. Be creative, don't be fixated on the idea that a tank has to take all the damage. Don't expect to stand on one spot while fighting elite monsters because you are the tank, don't play this like other games you may have played before. My final advice is to work as a team when possible. When I play with my wizard friend, we take turns casting crowd control spells. As simple as being frost nova followed by blinding flash can buy you 6 seconds of damage mitigation, which in D3 is a huge amount of time considering the damage your enemies deal in 1 successful hit.