I'm so glad to hear your trying them. Don't be discouraged, we all make bloopers when we first start out... and some of us still make them! lol
What are you using the paint on the joints for? Is it for a blush? If so, maybe try brushing on chalk pastels and gently build up the layers. I use prismacolor pencils for blushing. I rub one over a little sandpaper or emery board to create dust and blush it on with a soft make up brush. The trick is to build up the colour in lots of layers. And you will need to seal it all as well. I use Mr Super Clear matte... I find it works best. Hope that helps!