You can use projection shadows to generate soft shadows.
Save computations by using fewer lights or by reducing the distance they are visible from.
For blur effects, take a low resolution texture and blur it. This is faster and uses less memory bandwidth than blurring a higher resolution texture.
There are graphics techniques that generate reflections with relatively little cost but impose limitations. Consider if you can work within the limitations and so use these techniques.
Create a series of transparent white triangles around the object. Fade from fully opaque beside the object to fully transparent at the edge.