It was just countless trial and error. First I hit my delay on 18 seconds (wrong ID), then I hit my delay on 17 seconds (wrong ID), then again 14 seconds (wrong ID). It wasn't until I noticed that I was hitting the wrong second was I able to really narrow myself down. When I first attempted ID/SID abuse, my delay was in the 5900+ (I was aiming for 5779).
And with a higher delay, that means you have to hit the A button earlier to reach a lower delay.
Eventually I hit 14 seconds and a 5779 delay (I needed 15 seconds). Miraculously, right after I hit that 14 second mark on a 5779 delay, I hit the 15 second mark and a 5779 delay on my first try. I was extremely excited.
Now that I've had experience with ID/SID abuse, I can give you a few pointers that would prevent throwing you off (like they did for me). Once the time comes, I'll point out some things to watch out for.