How to setup a prefab before instantiating it?

I have a bullet prefab, which has a hitpoints progress bar above it and zero rotation by default.

The bar is invisible unless the bullet collides with other missiles. The rotation corresponds to direction of its movement.

However, when I write

Instantiate(Resources.Load("bullet"));

and call this instruction fast enough the initial view of the prefabs appears for a moment, which looks incongruously.

Using

(Instantiate(Resources.Load("bullet")) as GameObject).renderer.enabled=false;

doesn’t help.

This is the way for instantiate a prefab:

GameObject myPrefab= Instantiate(Resources.Load("bullet"), myTransform.position, myTransform.rotation) as GameObject ;

As you can see, you must specify a position and a rotation for the prefab instance.