I am sure your steps are correct. Here is what I do.
I use about 2.25 oz of corn sugar boiled in 12 oz of water, cool, and add to the wort in the keg. I purge a few times, test the seal, then set the pressure to about 5 lbs. I then check the pressure until it gets to about 20 lbs. Then I know that it (the yeast) is using the sugar to carb. I had a pressure gauge but dropped it. With the gauge I would keep the pressure about 20 psi. This pressure worked best when I cooled and tapped. Now I just wait a couple of weeks and check the co2 production by pressing on the gas pin lock. I don't know if this is the best way, but it works for me.