+-1/2 frame grid
As I discussed in the first part of the article in the Golden rule and editing accuracy section, it is very important which snap grid you use for Foley editing. A beginner Foley editor can usually see the difference of sync by 1-2 frames, but, gaining experience, the eyes and the brain begin to perceive differences up to 1/4 of a frame, especially in dynamic scenes. I recommend using snap grid + -1/2 frames. Nudging clips with a step of 1/2 frame is also optimal for footsteps and props fine editing, in my opinion.
Using pre-roll
The way a person perceives sync with ears, eyes, and brain when using a long pre-roll is very different from how we see sync when playing the sound using a fraction of a second as a pre-roll. Therefore, I would recommend using a couple of seconds of pre-roll to the targeted sound as a general rule.
It’s not just your eyes and ears that require a long pre-roll. Another factor that can cause inaccuracies in Foley editing when using a short pre-roll is that your DAW and codec may take a moment to stabilize, especially when using external decoders.
That's also why it is important to do double-checking and, in particular, to check the editing of the entire scene as a whole, from start to end on playback. At this stage, you check the sync not of each sound individually but watch the whole movie in a group with all the other Foley sounds.

The use of long pre-rolls in footsteps editing is especially crucial. As a rule, I do not put each step into a frame in the picture where we see the contact of the foot with the surface, but instead I create a footsteps bundle by progressively building an arrangement starting from the first step. Step by step. This definitely increases the time spent working on the material, but it improves the quality of Foley editing.
To help you understand what I mean, imagine that we have a character’s walk pass consisting of twelve steps. I mentally arrange the steps into three “bundles” of four steps each. Starting with the first step, I put it in sync by eye using pre-roll playback. Then I move on to the second, but I work on it in context, always letting the first step sound as part of the pre-roll. Next is the third step, and then the fourth. By this time, for the fourth step, my pre-roll is as long as it takes for me to hear all four steps in the chain. After completing the first four steps, I move on to the next bundle of the next four steps using the same method. Finally, I work on the last four steps.
This method allows me not only to do technically synchronous editing, but also helps me to compose organic and musical phrases. Working on a bundle of sounds is very different from working on each sound separately. After I've finished Foley editing all the steps, I go back to the first step and play the entire phrase of twelve steps from start to end. Believe me, even after such involved self-checking within the arranged footsteps pass, you will still find minor flaws that require subtle adjustments, both in terms of syncing and, possibly, in terms of the Foley artist's performance.
As I said in the first part of this article, Foley editing is a technical and, most of all, very creative work, somewhat similar to a musical one.