Not much difference. But I tend to think of things with each word. Such as "the stars twinkled at night". And "her dress shimmered in the moonlight". And "the ocean's waves glittered under the sunlight". Twinkle is when light appears to blink. Shimmer is a spread of shine over an object. Glitter is when you see sprinkles of light.

Hi, Glitter is different because it is a noun. Small metallic squares of plastic are glitter. Glittery would be describing something with a metallic shininess. We glued glitter to the poster tomake the king's throne look fancy and shiny. Shimmer is the slight movement of light on a reflective surface. When the whale surfaced the water shimmered on its back. Twinkle is a description of light. The Christmas tree twinkles with white, red, and green lights.

A star can twinkle. The air above a very hot highway (like in Australia) can shimmer. The surface of the ocean can shimmer when the sun shines on it. A disco ball can glitter. A dress covered in sequins (Блестки?) can glitter.