Yes, as far as I know most Echeverias are promiscuous. I don't know which ones may be self fertile, but the ones I've tried are not. All my Echeverias are pollinated by the birds and the bees.
My advice would be: get in there with a magnifying glass, or take pictures that you can blow up, so that you have a good idea about the anatomy, male parts vs. female parts, etc. Try to get a good sense of how the orientation of the flower axis changes over time (upward, downward, upward). Not all flowers which appear open for business are actually producing pollen. You need to transfer the yellow dots from one plant to the center part of another. A small paintbrush is often used for this.
I don't know if Echeveria flowers are protandrous but much of the family is, meaning the male parts reach maturity before the female ones do. So a recently opened flower is more likely to have active pollen, but one that's been open for longer (ie. lower down on the inflorescence) is more likely to have a receptive stigma.
Repeated visits are only going to increase your chances of pollination. Try different times of day, different days, whenever you feel like it or remember.
Try to be tuned into what happens after the flowers wilt, as the ovary dedicates itself to seed production, and the capsule breaks open and releases the seed. I can provide specific advice about how to best harvest seed, but the simplest approach is to cut the dry inflorescence at the base, intact, and put it head first into a paper bag. Shake the inflow in the bag for a while, pull it out, and there should be dozens or hundreds of seeds (fine, almost dust-like) at the bottom.
This is what you're going for in the end.
