Almost. You're doing good.

2. Set shutter speed and cock it if needed. Open the shutter AND aperture.

Most of the lenses have a lever to open the shutter for the purpose of composing without needing b/t. Sometimes this lever just works, sometimes the shutter has to be cocked for it to work. And the shutter speed should be set before cocking it.

4. Close the shutter and set aperture according to decision in step 1.

7. Flip over (so you know it's been exposed) darkslide and re-insert.

The easiest mistake for me to make is to not set the aperture in #4. Essentially shooting wide open instead of at the proper aperture.