I've built hundreds of cables in the last 2 years using looming and Ted is right about the hot knife, I quit using it for same reason. But, I didn't want to deal with the fray using tape, so I started using a lighter.
As soon as I cut the looming, I quickly heat the end with the lighter from the side of the flame for a second or two, then I take my finger and gently tap on the end while the melted looming cools, and I end up with a slightly open tapered end, like a funnel.
That makes it easy to "catapillar" the looming over whatever wire you are working with. Another trick, I don't cut the reel end until after I have pulled the looming over the wire and pulled it tightly to lock in the grip of it, then cut the end at the reel. Then I repeat the lighter trick.
Good luck !!