The cup is made out of two different meshes. Using the extrude tool I shaped the meshes to made the shape of the cup. To made the model of the liquid I added an edge loop to the inside of the cup model and selected the inside faces of the cup and shifted ‘d’ to duplicate the faces and then separated the new model from the cup. Now I can extrude and scale in the top faces of the liquid model and merge the final face to the centre point.

Adding two edge loops to the outside of the cup I then selected the area and duplicated it by using shift ‘d’ and once again separating it from the cup model. Afterwards I added a solidify modifier to the mesh.

I used a curve to make the straw of the model. Reshaping the curve to the shape I wanted. I then changed the curve into a mesh which allowed me add thickness to the straw.

By turning down the metallic settings and changing the blend mode to alpha bend I can make the material for the cup look like it’s plastic and see though.