You will want to use glass jars with tight-fitting lids for storing materials and for aging completed blends.
Jars protect the materials from insects and keep essential oils from evaporating.
Amber or dark green glass jars work best, as they will keep out light which would otherwise fade the colors. However, any jar with a tight-fitting screw cap can be used. Label all jars and store them in a cool, dark, dry place. Eyedroppers are very useful for dispensing oils. You should have one dropper for each oil you use, and it is a good idea to have some extras.