One great DIY project for mason jars is to turn them into solar lights. Homeleo Solar Jar Lid Inserts fit most mason jars, come in 9 colors, and 5 sell for $22.99. Hanging them is as easy as attaching a wire handle.
You can also create beautiful luminous decor by splattering glow sticks into jars, or using glow in the dark paint.
To create the awesome D.I.Y. mason jar lamps show below start by purchasing glow sticks or glow in the dark paint & mason jars, safely cut open the glow sticks if needed, place the desired amount of liquid in your mason jar, put the lid on, and shake.
I also strongly suggest experimenting with clear iridescent glitter.
Photo Credit, Top to Bottom & Left to Right: Hanging Mason Jar Wedding Reception via the CrazyForUs Blog, DIY Glitter Mason Jars via Mason Jar Crafts Blog