I Always mix lots of different textures together. Art yarns will be showcased better if you use more simple yarns with them. It will also keep the overall weight lighter. You can do two rows of art yarns with two rows of singles, when knitting or 4-5 rows of singles then 3-4 of art yarns.
First time using art yarns? Try one skein to knit or crochet mittens wrists. I use 8-10 mm needles or crochet, and go looser when needed.