depends really on what point in the game it is. Playing behind early (all towers up?) or after lane phase (at least 1 tower down)
can be really different and this is all assuming that lane phase is over, 1 or more towers are down
so if you are support you have maybe 2 MAIN jobs that you have to do. 1 is make sure you are rotating to your stronger players (look at your TAB and see who is doing well) and then you need to make your way there but also be focusing on clearing out any enemy vision in your jg or in rivier as well as putting vision down for your team so they can safely farm without being collapsed on.
Generally speaking If i am leaving my AD I at least try and give him some sort of vision line in the enemy jg so he can at least see "Hey they maybe coming" generally tho they shouldn't be pushing past river anyways but often times they will.
When you get to whoever is strong your goal is to keep them alive but also direct them to other objectives while trying to avoid any team fights since your team is behind they will be significantly weaker.
Farm is really the name of the game, if your jg is dead or behind I take their farm because most jg's are not going to be worth much mid-late (unless it's like a yi or something) your goal is to get farm, look for lanes that maybe pushing to you where you can easily go and pickup the farm.
If your team is way behind then you really shouldn't be doing any team fights 5v5 aram style, you should be looking for picks in your jg (which is why vision control is important) so you are actively looking for ppl who wander into your jg alone or maybe 1 person and trying to kill them. That's basically (as well as picking up farm in lanes and jg) how you get back into the game
but just ARAM 5v5 is the worse thing you can do, as well as forcing things like Baron when way behind without first clearing vision.
You can for sure get Barons and Drags when behind but you need to be really aware of where the other team is..Like if you have already cleared out vision in baron/drag and then you see 3 ppl on enemy team on opposite end of the map then that is a great time to try and sneak a baron or drag.
Also being aware of who is strong on the enemy team and if they have TP or not, cause if nobody has TP that means you can push further without being collapsed on as quickly..
