Ways not to die when joining a random or static group and ways to avoid killing party members:
1) Get 3 pairs of boots "anger steps" at the korthos island quest "Sacrifices". It's an end reward, clickies, +125% speed. Without it, or any high speed boosts... you can die in many situations. Even when a party seems to be playing together they may split or a party member may move to a different room and get in danger and without speed they or you can die. It's also good to scape obviously.
2) Do not join groups with only one or two members if they are already inside. (regarding this, many groups start quests with few members because they know that this may make people join them.) But if you do and they move too fast... consider if the danger in the area is too high or not. If it seems it is... and they do not answer in chat... probably there is a high danger of dying specially if your character has not too many ways to scape difficult situations (like reapers, high quantity of enemies surrounding you). In such cases either be fully prepared or leave, like I wrote before, in the case that your character has not too many resources.
3) Do not try to do "just this quest the two of us alone"
4) If the party members only communicate through voice chat and refuse or simply ignore chats consider it a high danger situation. If they are too focused in completing the quest by their own you can expect that they don't care at all about what happens to the rest of the group.
5) If you enter a group and party members go too fast and you can not keep up with the speed or don't communicate where there are traps, read the wikipedia inmediatly. Take into account that they may or may not know where are the traps too. Don't open chests if they are not open already and don't get close to them. Consider the shape of rooms and architecture and inmediatly tag weird looking ones as a possible trap (if you did not read the wiki, and watched the map) If they are druids, barbarians, monks, or trappers, consider that they may be jumping over the traps, and you may or not be able to emulate them. Always consider jumping over traps too risky in all cases unless you already did it many times (your character has a lot of evasion)
6) When following the group always match their steps. They may be moving around a trap.
7) Watch through corners of walls and both intersections and kill the most dangerous enemies from afar.
8) If you are tired, stressed, worried, or nervous, consider to stop for a few seconds, or minutes if the rest of the party seem to be faster than you. In all cases you can stay in the back and help whenever the group gets difficulties, you don't need to be the heroe or get kills counts.
9) Retreat to safe areas and not to unexplored areas when in situations you consider are too chaotic. (although sometimes enemies may spawn in safe areas too after they have been cleared)
10) Always kill casters first, reapers and champions. Get elemental protections apropiate for each quest so casters do not kill you.
11) Do not start looting after killing what seems to be the last enemy. There may be more and spawn while the group is looting chests: some looting, the others getting ambushed by a horde of final enemies.
12) Do not leave the dungeon while party members can not do it yet. For obvious reasons.
13) Make alias macros for dangerous situations like "RETREAT TO SAFETY NOW" (If I remember correctly they can be coloured too).The alias macro can be aliased as few as one letter and so typed very fast. (if you use mic you can use the mic but some people have the audio of the mics muted and if you use mic make sure you say it loud and clear (so everybody understands you) but also in a calmed tone. (some people may not understand your accent btw or your expressions.) Ask multiple people if they understand what you are saying in mic. (some people argued my mic was too loud while others said they were not able to hear me. I on the other hand, find out that mics in ddo are barely audible and obviously I am not going to mute all the sound and leave only mic audio. That's why I always chat instead. Chatting takes only few seconds. If group can not chat and refuse to use it after they are safe they are too impatient or inept and that's very bad in the first place.
14) If you use mic always write important instructions. Chat can be read and reread. If you want to die because someone afked for two seconds or a claxon in a nearby street made them unable to hear you, it's your fault.
15) Buy potions of aid if you don't have aid as spell. It's free life and cost only a some platinum coins. You can buy hundreds. You can buy other kind of potions too, you don't need spells constantly. Hoard clickies too like mana recovering clickies.
16 ) The group leader needs to change lfm and add new members as well as to answer their private messages. Let them time to do it. If they stop it may be because of that. If they stop and you don't (even if they are not actively leading) it's probably your fault if they can't help in a fight or other situation. Shrugs
17) Get new equipment every new level of experience
18) Better play reaper 1 with good group than zerging elite. It's so easy and boring you will eventually die to a trap, or any other thing. You will become too confident. -> This last one is my personal opinion.