I'm a dk tank (as you could probably tell) and I read on elitist jerks that death strike should only be used when the healing is more than the minimum but I also read that it should be used as often as possible and wanted to know what is the best way.
It's a complex question I know it's probably based on the fight but I just want a general idea.
Thanks for any replies.
It's tricky. Because of the way runes refresh, it does not need to be used right away. You do not lose anything untill both sets of unholy/frost runes have finished cooling down. Therefore, you want to use it at some point between a set of runes being available and the next set being available but because of rune procs, you will likely be waiting on Runestrike too if you are sitting on runes (Runestriking without a fully depleted rune can waste a rune proc). The best time to use it is when the heal will be the largest during each of these windows. Determining when it will be the largest cannot be 100% Determined. You just need to take a guess.
If you watch your health closely, you will notice times when you take large spikes of damage. Just make sure you have a DS for as many of these large spikes as possible. Don't worry so much about the smaller ones. And don't DS if it is going to heal for very little. In the worst case you end up sitting on all 4 unholy/frost runes and have 2 DS's available for the next spike. If damage is so low that this is happening just use the extra runes for Heartstrike/Bloodboil. The healers won't notice because damage is low.
Basicaly, stacking blood shield and self healing while damage is low is not going to make much of a difference in your healers ability to keep you alive. Stacking blood shield and self healing when damage is high will. Don't waste DS on low damage and small heal amounts if doing so will put you in danger when a big spike happens in a couple seconds. But at the same time you do not want to just horde runes in anticipation of some huge spike that will never come. You need to be casting as many DS's as possible. Judging it properly will just come with time and knowledge of the content. Just pay attention to your Health and get an eye for spotting the spikes.