Triple tir optics like carclo or ledil cute-3 is widely used and recommended for newbies. You dont need to find any holders, led centering rings, play with their height and etc. You just take any suitable pcb, place optics legs in right holes and thats all. No extra tune-up needed.
Cute-3 optics was developed long time ago, it was made for old leds with big dies and bubbles on top surface helps to mix colors in rgb bulbs (MR16 standart). This bubbles dont help with strong hotspot, some users sand them flat but I dont have such experience.