I'm an archaeologist, so I've spent the better part of two decades thinking in chronologies and typologies, so I have - of course - divided the connections into categories.
1. Spliced loops.
2. Whipped loops.
6. Loop and knot.
7. Attached loops.
1. The spliced loops are created by stripiing off coating and splcing the core into itself, creating a loop. These can both be "naked core loops" (1a) and "coated loops" (1b).
2. Whipped loops can also be both naked core and coated (2a and 2b).
3. Welded loops can also be both (3a and 3b), although *very* few choose to weld a loop with a naked core, but some do, and it's possible, although fiddly.
5. Knots are used by some, and is certainly the most elegant solotiuon, and the most elegant is a mono shooting line needle-knotted to the end of the shooting head. But - it sort of defeats one of the core purposes of using a shooting head, namely being able to switch to other lines in an instant.
6. Loops and knots are fair popular, where you have a loop on the end of the shooting head and the knot a (monofilament) shooting line to the loop.
7. Finally attached loops are usually loops made of braided line (made using a splice) which is then attached to the shooting head and/or shooting line. In this category I use stripped flyline core to make a small, flexible loop on mono shooting lines. The shooting line is both inserted into the braided core but also knotted to the loop.
Two naked core loops are small and go almost unnoticed through the rings, but they have one major drawback - they can be *very* difficult to pull apart after big fish or heavy snags.
Two coated loops are almost always quite easy to separate, but are more prone to catch on the rings (especially if you use single leg rings, which is why I have an HT 6 with snakes).
I'm not sure whether there'll be videos or articles, but over summer I'll elaborate on the subject, and maybe make a front page on each category showing how to make the loops/connection and go through advantages and disadvantages.
The PoD is an older picture, which also shows some of the possibilities in colour coding the loops.
Have a great weekend!