I’ve messaged affiliates before but not often. Most of the time it’s chicken and egg – the better affiliates contact you once your WSO has hit a certain amount of sales (varies by affiliate). If you do reach out, give them review access and a compelling reason to even think about promoting your offer.
Muncheye can be useful in attracting affiliates – just allow long enough for the thread to get approved.
Not much organic traffic in places like the Warrior Forum (that’s been fairly quiet for some time now) or elsewhere. It’s more down to the “noise” you can create yourself.