Ropes Lines and knots; pretty basic........ NOT!

I have always used the kitchen gas stove to melt the ends of my lines together, but sometimes the perfectly melted outer does not melt to the perfectly melted inner line, creating a perfect disaster..... Any tips to the perfect the perfect melt?
Also, the prusik hitches look great on the LLM boom

And they're VERY easy to slip fore/aft on the boom to adjust. Once I find the perfect place, the rope through the boom might be more permanent, but this looks great
Thanks again for the help
John