Heroism and Mages
I might as well put this in the forums instead of telling people one by one. If you are a shaman and you are in the same group as a fire mage (all our mages are fire) you should be using heroism at 20% of the bosses life, unless the fight mechanics call for it earlier (eg Gorefiend). The reason is because fire mage dps increases by 20% for the last 20% of a boss and stacking trinkets and heroism at that time gives a significant dps boost. This also gives the rest of the group the chance to save trinkets and such for heroism because they know when it will come.
I might as well put this in the forums instead of telling people one by one. If you are a shaman and you are in the same group as a fire mage (all our mages are fire) you should be using heroism at 20% of the bosses life, unless the fight mechanics call for it earlier (eg Gorefiend). The reason is because fire mage dps increases by 20% for the last 20% of a boss and stacking trinkets and heroism at that time gives a significant dps boost. This also gives the rest of the group the chance to save trinkets and such for heroism because they know when it will come.