Fireteam and Communication
If you’re serious about dominating in PvP then you’re going to want to get yourself a fireteam equipped with microphones. While it’s not necessary, it makes winning matches significantly easier. For one, if you play with the same people frequently, you will naturally build up a flow over time and start to coordinate with one another. But also, being able to communicate with your team members is an essential capability for strategizing.
If you can’t get a fireteam together from your friends list, you might want to try joining some Destiny FB groups or scavenging the Destiny LFG websites. If that doesn’t work, or you just can’t be bothered to endure the extra time, then you should at least try switching your audio from fireteam chat to regular team chat to communicate with any of the other random players on your teams, provided they’re also on their mics looking to communicate.