If you are thinking about sculpting or painting your own knicknacks, decorations, or embellishments, there are a few things you should know, and a few things you need before you start.

Clay or modeling compound:

plain old playdough just wont make a nice, crackfree surface for your figures. Instead, search for a smooth, moldable compound.  Fimo is a great, heavy compound, dense and tough.  To work with fimo, it needs to be worked before sculpted. Knead, pound, and mash the clay before trying to sculpt for smooth, even, maleable results. It needs to be baked to retain shape, and make hard!
For a nice, lightweight compound, choose foamdough, such as the Model Magic (c) line of compounds.  This clay is so light, easy to work with, does not need to be worked before use, and does not need to be baked before painting and finishing. Dries within 24 hours. Light enough to use on paper or cardboard products without adding extra weight.  And it adheres to itself without pressure or smoothing.   just dont let your figures touch eachother before they are dry, or they will stick to eachother.  This compound is my favorite, and is what i choose for all my sculpting and crafting!

Tools:

You will need a couple of simple tools for your sculpting. Choose duller tools if using foam compound. You can use pretty much anything to make indentations. Pencils, screwdrivers, scissors, pins, and picks make great eyes, holes, and patterns on your dough.  make sure you put the indentations in your sculptures BEFORE they are dry, or your sculptures or figures will crack.  If you are making a large amount of identical figures, you may choose to use a mold. make sure, if you are using a foam compound, that the mold is smooth, metal or hard plastic, and you trim your seams BEFORE drying.

Painting:
For your dough, you can use ANY oilbased paint, and a few of the waterbased paints as well, as long as you put many coats on your work.  For fast drying, smooth looks, use several thin layers of paint intstead of one thick layer.   You can also use glitter paint, or if you want a dust of glitter, use powder glitter on top of your paint, without smearing it in.

Sealing:
For figures that you are going to be using on paper or cardstock, choose a papersafe sealant, such as MOD PODGE. it is a shiny glossy smooth sealant, and will make your figures dry hard.
For other figures, ModPodge will work well too, but you can also use an acrylic sealer. use ONLY one brush and ONE pallete for your sealant, and use only ONE coat of it.  too many coats will make peeling a good possibility, and that will ruin your finished product.

One more tip.... Just have FUN!     there are all sorts off possibilities. Shapes, buttons, animals, people.... your creativity is all that limits you, so just enjoy yourself, and if you try something you dont like, you can always start over, try again, and again, until you get a result you are pleased with.