First you put some icecream in a blender and then add some milk to it before you blend them together. And after blending them together you should use your caramel or any other syrup of your choice to decorate your glass cup to make it look presentable.

Another thing to consider too is for the milkshake you must not use oreo or Maltesers,just use any chocolate of your choice that you feel you can afford, and it's not compulsory to add whipped cream to it, coz it's costly and it's not everyone that can afford it.incase you don't have it don't stress yourself to buy it,just use what you have and trust me you will really like it.