I think the blood knot is probably the hardest for me to tie. I use furled leaders so I don't make my own leaders anymore which is what I mainly used the blood knot for. The only time I use it now is when I attach braid to the fluorocarbon backing on my spinning reels. That's fun since braid is very slippery. I got pretty good at the Bimini twist since we used it for off shore fishing. It's easier to do when tying it with 20, 30, 50 or 80 lb Dacron. I just had to get creative when making one seven or eight feet long. I use the improved clinch when attaching flies, lures or hooks these days.