I did this in the past, if I remember correctly.
Post your Instagrams get fellow Oppo-follows.
I think with all the spam bots that follow people, best way to know if they are from here is just comment on a random picture “Oppositelock” or “from Oppositelock”.
Here’s mine: (Drop that comment on any pic and I will follow you back within hours)
PSA - Please don’t post your Instagram name if you don’t intend to follow any Oppos. That does nothing for the point of this.