If you are having trouble relating to your little children, perhaps you should change your approach. Let me ask you something; Do you have homemade play-dough residue under your fingernails? Do you have some old clothes, somewhere, that are stained from finger paints and water-colors? If not, you should get you some. Here is a simple approach to play-dough/Papier Mache mentality:
The principle difference between Play-Dough and Papier Mache is the amount of water: you're either making "biscuits" or "gravy" -both are edible, but not desirable to eat -i.e., you could live on it, but it tastes like... salt.
There are only three ingredients to both mixtures: FLOUR + SALT + WATER
The reason for the FLOUR is to 1) give it substance and 2) help it to harden. The SALT is there to 1) make it undesirable to eat -even to a little kid and most dogs (there are exceptions, of course!) and 2) to cause the dough to dry out faster. The WATER is only there as an emulsifier (in layman's terms - it makes it wet).
Start with the FLOUR: this tells you how much dough/mache you are going to make. If you are using 2 Cups of flour, for instance, you won't get much more than 2 Cups of dough BUT (and this is important) you will get anywhere from 4-6 Cups of mache -depending on how thin you make it. Biscuits -Gravy, your choice.
Next comes the SALT: In principle, use enough salt to do its job (see above) but not TOO much. Don't worry -Play-Dough/Papier Mache is very forgiving. "Not enough" salt will make the dough dry too slowly and, thereby, allow the flour to mold before it's dry -NOTE: you'd have to be WAY off to get "not enough." We put a sprinkle of salt on our food -that's "to taste." We put a half-teaspoon, or so in a recipe to flavor the whole loaf. Salt is potent.
For two cups of flour, 1/4 to 1/2 cup (that's right, "cup") is plenty. If you add too much salt, the dough will die of thirst, literally. The flour will not bond to the other ingredients because the salt will cause the water to dry up too fast. Now, blend the flour/salt mixture so that it is evenly distributed.
The last thing you add is WATER. Cold water is inhumane. If you want children to actually stick their hands in it -don't use cold water. Hot water is out of the question because, chances are you are using self-rising flour. Hot water will "activate" the flour and mess up your recipe -it will begin to cook. We use "tepid" warm water. Something that is pleasant to stick your hands into.
This is the only "hard" part -it's the equivalent of cooking microwave popcorn without a preset button -it can be done, but you have to pay close attention or it's easy to overdo it -and we ALL know what it means when the microwave popcorn is overdue!
How much water is the key to everything else that happens. If you feel confident enough, you can draw the water straight from the tap, otherwise, have a smooth-pouring vessel nearby, filled with tepid water. It doesn't hurt to have an assistant, at this point, to pour the water while you stir the ingredients.
Add the water slowly, If you are making Play-Dough, you have enough water when the dough begins to "pull away" from the edges and takes on a consistency like biscuit dough. If you want it to harden rather quickly, make the dough stiff. If you want it to last a while, make it a little thinner. There will come a point when you can lay the spoon down and begin working the dough with your fingers. If it's still too tacky, sprinkle some flour into the bottom of the bowl and roll the dough into it and work it some more. Eventually, you should be able to work with it and not have it stick to your hands. Now it is ready.
If you want your project to dry out, leave it out overnight and it should do the trick -as long as you don't make the pieces too thick. Air drying is the principle at work, and once the dough begins to harden, it can form a thick, hard surface, but still be "wet" on the inside, which can encourage mold and mildew -you don't want that.
If you want this play-dough to be reusable, you can store it in a plastic zipper-bag (has to be airtight) and it should last for a couple of weeks. If it begins to stiffen with age, carefully add a little more water and work it in with your hands until it is pliable again. If this makes the dough too tacky, once more, roll it in a little flour and work it until it no longer sticks to your hand.
Add the water more quickly, if you are making Papier Mache, you have enough water when the mixture takes on the consistency of pancake batter. You can make it thinner by adding more water -if you go too far, however, you have the option of adding a little more flour. Bear in mind that the principle behind Papier Mache is to take strips of newsprint or other light paper and drag it through the mixture before applying it to whatever project you are working on. If you make the mixture thicker, it will "glob" up on your paper strips, if you make it too thin, it can get your paper too wet and cause it to fall apart. All of this takes a little practice. Don't be afraid to try again.
Some people like to ADD COLOR to their Play-Dough. This is simple to do, but not always easy. Remember, Play-Dough has just three ingredients. To add a LIGHT COLOR to the dough, add food coloring to the water before mixing the ingredients, however, if a BRIGHT COLOR or DEEP COLOR is desired, you should completely replace the water with whatever color you choose. You don't have to limit yourself to standard food coloring (which usually comes in only 4 colors: Red, Yellow, Green and Blue -there are more expensive colors available but hey, this is play-dough after all, isn't it? how expensive do you want to make this?
Some alternative color sources include Cranberry Juice; Grape Juice; Pickle Juice; Apple Juice; Olive Juice -bear in mind that a "clear" substance will bring more desirable results. For instance, Tomato Juice doesn't look too keen, and it makes an unsightly finished product when it dries. If you are using standard food coloring, mixing colors can be fun, as well. You also could get an "egg-coloring" kit, around Easter season and use those colors instead.
Some other ways of decorating Play-Dough/Papier Mache after the fact, is to use poster paints after the solution is completely dry, adding your detail with a paintbrush. Or, while the solution is still wet, you can apply glitter, or some similar decorating material, such as confetti.
If you intend to "bake" your play-dough, make the mixture stiff (less water) and work quickly with it, before placing it on a sprayed or greased cooking sheet. Try not to make your items too thick, this will allow even cooking and help prevent splitting. Bake at 350 degrees Farenheit, and keep a close watch on it, DO NOT LET IT BROWN. We are not baking cookies here, just rocks.
If you find that you are a complete failure at these activities, don't despair. You can always skip a rope with your kids. The point is to get involved in something that is important to them, not (necessarily) you. Who knows, you might enjoy being a kid again, so much, you won't want to come back to adulthood. Whatever you do, have fun -your kids will enjoy the activity a whole lot more if you do.