For a true system style approach you would need to replicate the move and hold at least twice up the board. So you are repeating your movement pattern and grip type. I would decide on what you are wanting to target, a good starting point is a weakness. Mine would be shouldering gastons, so I'd build a move to mimic this that is pretty close to my limit, and duplicate it up the board. You could also combine targets... Shouldery gastons into a pinch for example.. Infinite combinations obviously.
The advantage of having your own set up is you can constantly tweak the set up, you'll be very lucky to set it up and be happy with it first go.
Once you have an exercise set on one side then mirror it.
Setting up as mentioned above with a spirit level is a good call, you could also set out a grid of 100mm squares using a chalk line (just mark up the top, bottom and sides and draw the string across), you can get chalk lines for not much more than a fiver of eBay or a builders merchant. Then use the grid to locate holds.
