I don't like that cheap split loom, as it reminds of what the wire chasers put on everything, lol. I mean, it has its purpose, but there are other alternatives.
As for tape, use a 3M non-sticky electrical tape, or a textured cloth type tape if you want an oem look; the non-sticky tape is actually waterproof also, unlike reg. electrical tape and is quite durable.
If these are new connections, shrink tube works well; they make split, wraparound shrink tube also, but not sure how well it works. Can also pull the wiring thru nylon, alum. or ss tubing (use caution on metal though!) Also, they make SS (or plastic) braided sheathing that looks good and protects; this can be in the type that you push/pull over the wiring, or the wrap-around style if existing harnesses.
I'd recommend going to mcmaster.com and checking out their stuff for ideas and go form there.