Read labels and instructions thoroughly. Paints, sealers, and adhesives will have a black and white label on the bottle that clearly indicates whether or not the product is non-toxic. Such products are good for children to use and rarely would necessitate a face mask or gloves. Beware because when working with toxic products, it is very easy to become accustomed to the odor, and subsequently forget we are breathing unhealthy air. Try to work outside if at all possible.
Glue guns cause lots of crafters' injuries.
Use low temperature glues instead. These are oval-shaped, while the hot temperature glues are round in shape. Regardless of the materials you're handling, always wash your hands before, during, and after crafting.