It's definitely a good idea to put fake egg/golf balls in the nests as 'bait' to show them it's good safe place to lay.
I'd put them in all but one or two of the nests, I had a pullet that didn't like them at first and would lay in the nest until I removed the fake egg.
Nests should be about a foot lower than roosts(so they don't sleep in nests and poop them up),
and easy to access both up and down, a perch about 8" in front of nests (if they are off the ground) gives them a place to land and take a look before entering nest.
My new layer notes:
New layers can be quite goofy acting, they don't know what they are doing at first and can be confused and anxious, it can take up to a month or so before they get it all figured out. Putting some fake eggs or golf balls in the nest might help show them where to lay. They may scratch around in the nests for weeks before laying, spreading the bedding everywhere.They will scratch around a bit less in nest as they get used to the routine. Meanwhile, eggs everywhere, some of them can be rather funky looking, soft or thin shelled, huge double yolked eggs.
Signs of onset of lay---I've found the pelvic points to be the most accurate.
Squatting:
If you touch their back they will hunker down on the ground, then shake their tail feathers when they get back up.
This shows they are sexually mature and egg laying is close at hand.
Combs and Wattles:
Plump, shiny red - usually means laying.
Shriveled, dryish looking and pale - usually means not laying.
Tho I have found that the combs and wattles can look full and red one minute then pale back out the next due to exertion or excitement, can drive ya nuts when waiting for a pullet to lay!
2 bony points on either side of vent:
Less than 2 fingertip widths apart usually means not laying.
More than 2 fingertip widths apart usually means laying.
Egg Laying Timing
It takes about 25 hours for an egg to form, a new ova is released shortly after an egg is laid.
A new egg could be laid approximately every 25-26 hours, so an hour or so later every day until one is laid late in the day and another ova might not be released until the following day, so a day off. BUT..very hen is different and only time will tell what a particular hen/pullets schedule might be. Not every hen/pullet lays every day..some only lay a few a week.