That too, see and feel the result as if it’s happening, or just about to happen, and how that’s going to look and change things. Notice how you feel about the changes and feel the satisfaction/triumph/happiness of whatever this does for you as if it’s already a done deal.
This is part of the “law of assumption”.
What you don’t want t o do is dwell on what you don’t have. The universe doesn’t hear neagtive very well, and if you put your energy into thinking about lack, you will manifest more lack the same way you would manifest success.
Energy follows mind, meaning it flows where your attention is, and what it does when it gets there is set by your intention. Your intention is for success not more of the same old.
That’s great, but try this psychological trick - work it as if it’s already underway and a given. You WILL become what you wish, because YOU said so. You are the operator, the creator being, you are the pinnacle of this working, so stand in your power, feel it and let your will unfold and start acting in your life, with the help and inspiration of these powers.
"Lucifer, Asteroth, Kateron, I request your assistance in becoming the most creative, most influential, and most versatile musical artist. I desire to be able to fully express myself through music and through my lifestyle. I WILL improve my musical artistry and creative expression.”
You seem really smart and articulate, and you have the detail orientation to have gone through the whole thing, so I’m going to say this is YOUR magick now, your ritual, and they are the correct steps because you said so, and you are the Operator.
If I were going to work this ritual for me, I would edit it to suit my way of being. This would mean departing from their instructions slightly. First of all, nobody needs Lucifer’s permission to contact Astaroth or Kateron. If he’s not involved in the work and doing something useful, I would skip Lucifer altogether - “participants only, no spectators” 
After that it’s a perfectly good pathworking. You will get the entitles you intend to get.
I do suggest you cleanse the area before you start to clear out any astral time wasters looking for a free lunch and again afterwards. Doing magick makes you shine, and it attracts attention from the riff raff and wildlife.
We have info on setting up wards and protections from lesser astral beings here: