Glass painting can be done both on plain and textured glass. Technique depends on the design you are using. If the glass pieces are not very bulky you can use Fabric Glue.

You can get various sizes of mosaic glass from any tile shop.

Aanchal it is always better to use acrylic sheets for 3D glass painting instead of actual glass. I don’t know where do you live but you will get it easily. You can use fevicol or araldite.