At first I added the straws together and cut a little to make them enough long for my project.
I inserted two LEDs at the ends of the straws and used heatshrink to make it tight.
You can use just one straw to make a LED glowstick throwie. On my project, power wasn't a problem but if u want to make a portable project with 3 volt batteries like CR2032 u must insert the LED just one end of the straw and close the other and with a tape or something. Or u can insert a burned (dead) LED as a mirror for more light effect.