I have never mated dilepis chameleons, but I have mated other species....so generally...I show a female to a male so that the male can see the female and watch the reactions. If the female hisses, gapes, darkens her colors, sways back and forward, then she is unreceptive/gravid. If she remains calm and doesn't seem to be bothered by the male's presence, then I put the female into the male's cage. I continue to watch to make sure that things go well...after the mating, I remove the female.
I will try to remember to give you information on incubating eggs and the egglaying procedure tomorrow...I have to sign off for tonight.
Here's one more site with information that might be of help though... http://members.tripod.com/chameleons-1/flap_neck.htm
"At mating time, when the female exhibits yellow spots on the green ground color, the sexes are put together. The female reacts either with slow flight or she remains perched on her branch and threatens mildly. The male approaches very impatiently; often he does not court at all. Copulation takes place in the usual manner and lasts a total of about 20 minutes About 30 to 50 days after mating, the female lays between 19 and 58 eggs. The eggs should be put on moist vermiculite at 28°C (82°F) in an incubator."
Please be aware that the site I gave you was for the breeding and incubation information. There are a few things I disagree with concerning the husbandry in the site (no mention of UVB, use of substrate, for example).
After the successful mating...
You need to provide her with a place to lay the eggs. What I do is put a container in her cage that is big enough for her to fit into when its empty with a couple of inches of space on all sides. I fill it about 2/3rds full of washed play sand....this is intended only as a place for her to start to dig to tell you that she is getting ready to lay the eggs. I then move the female to a modified rubbermaid container. Its a 65 liter container that I have cut away most of the middle of the lid of. I cover the hole I made in the lid with screen. I place at least one bag of washed play sand that I have moistened so that it will hold a tunnel in the container and a branch for the female to climb on. Some people place a large stone in the container and/or a plant because often a chameleon will dig her hole at the base of either. Make sure that the stone is resting on the floor of the container so that she can't dig under it and have it end up on her. I put her in when she is ready to lay the eggs and put the lid back on the container. Over the screen part of the lid, lights can be placed...but be careful not to overheat the container. Water can be sprayed on the sides of the container so that she can drink. She can be fed while she is in there too, but remove all the insects that she doesn't eat so they won't bite her or her eggs.
Do not let her see you watching her while she is digging or she may abandon the site. If she abandons it often enough, she could become eggbound and die.
Some chameleons dig the same hole for several days...others dig a couple of holes before they decide on the one they will use. The female may return to the branches each night or she may sleep in the hole. Once she is done laying the eggs and burying them completely and has returned to the branches, the eggs can be carefully dug up. I always try not to turn them when I move them to the incubation container.
The incubation container can be a shoe-box sized plastic container....and should be prepared ahead of time. I punch one or two very small holes in the lid. I fill it half full with slightly moist vermiculite. (Unfortunately, having never hatched/incubated flapneck chameleon eggs, I can't tell you the moisture level that is needed for this.) I lay the eggs in the container in rows in small indents. (This works for veiled eggs and some other species of chameleons as well as lots of other lizards, but there is controversy over whether some species' eggs have to be close together in order to hatch and I can't tell you what works for flaps.) Put the lid back on and place the container somewhere where the appropriate incubation temperature can be met. (Again, I can't give you specifics.) You will need to make sure that the eggs don't dry out....but you also don't want them to be too moist or the eggs can take on too much water and burst.
The eggs should grow from the time they are laid to the time they will hatch. Just a few days before they hatch, they could sweat, shrink in size, get odd patches on them that we refer to as windows (thinning of the egg is likely what it is). The baby should cut an x-shaped hole in one end of the egg and poke its head out. It will lay like this for a while (looking dead) while it absorbs its yolk. Its always said that if a chameleon can't get out of the egg by itself, it won't likely survive...so I don't usually help them out of the egg. (They can spend up to a couple of days laying in the egg with their head stuck out.) Once the baby has come right out of the egg, move it to a cage to raise it.
If the eggs are separated by an inch or so in the incubation container, they will likely hatch more individually so it can take some time for them all to help. If they are incubated close together, they will all hatch at almost the same time.
Sorry I couldn't be more specific on my information in some areas, but as I said, I have never incubated dilepis eggs.
I hope this helps and that you have success breeding them!