It's been my experience that scheduling calls the night before to release you about 90% of the time. Sometimes, but not often, I've also gotten a call from the LCA releasing me. Only once was I required to go to the airpoet before being released and I *believe* that is a LCP vs LVP thing. If I don't get a call by 7 or 8pm base time the night before a trip with training on it, I have just called scheduling and been released with no problem. This has been my experience for full trip drops. Partial trip drops are a bit more inconsistent.
I guess I'll consider myself blessed!