Hi Bluenose2
If you have already got the Loomaline then it is probably worth giving it a go. I also have one, and used it with reasonable results.
I would not simply take the plan's looming recommendations. I have seen them with recommendations such as use the horizontal pins A, B, D, F and vertical 8 but that will always be dodgy.
I found that making a scale paper template of ratlines works for me. Then use pins A, C, E , etc and then adjust the vertical pin number to get the desired angles.
You can either make the ratlines as one single continuous, up and down around the pins. Alternatively, you can tie off the individual lines to the lower pins, and tie the bundle to the top pin. The second method is harder as you will get variations in the tension but it may be necessary for special cases.
As you can see from the picture, I put white paper to cover the bulk of the jig. I found the black frame hard for contrast. Having a simple white background helped, and I could put guiding lines there too, to help alignment and show the starting position.
I am sure that others have their own favourite methods, with their own jigs, and maybe other tips too.