When it comes to the new light party dungeons, I usually ask if the others are fine with one blind attempt on the bosses before they shed around the advice. That's only three other people and most of the time they are quite fine with it. When it comes to the larger group content I'm quite fine with getting some information before the boss, but I sorta don't like the huge text wall / ascii graphic help macros. Mostly because they are so spammy that they stop being helpful for me. Preferably on the first attempt with new players give out few notes that while failed can kill whole group but not try to explain the whole fight. It just goes over the head before seeing the stuff.