Carrying as a Tank or as a Support or as a Support-Tank ?
**Tank : ** Peeling for your carries & counter-engaging against the enemy engages unless it's to your advantage to initiate. I find that in most cases it's usually more effective to counter-initiate unless you have back-up rather than to initiate unless you have a very strong initiator or wombo-combo initiate.
Support : Some supports can transition into APC.
Support-Tank : See above in the tank-section, but more than that, you need to be tankier than the enemy team's tank/support/burst/etc., for best chances of winning in early fights/skirmishes, even if you're putting off the Sight-Stone until after you've obtained a Cinder-Hulk (much as this may seem counter-intuitive for a support-role, sometimes it is necessary, depending on how likely fights are likely to be forced, such as against a lane with a Thresh).
Rest of it is a matter of pinging objectives at the right time, pinging where your allies should be on the map at the right time, when they should back off via V-Pingingg, always warning of danger any time ANY of the lanes have gone MIA (ping the paths in which they're most-likely to head after they've disappeared from lane followed by a warning ping), make sure pings are focused on the right objectives (i.e.: you cannot be pinging everybody to focus a tank unless their team-formation is such that you're forced to go through the front-line in order to get to the back), ping to grab turrets instead of chasing past, end game when inhib is targetable instead of wasting too much time on side-lanes when you can end it immediately, and make sure everybody backs off via pinging them away starting from when enemy death-timers are only 10 seconds remaining (this is the time to GTFO so that you don't get home-guard countered).