On C+F fusing:
Take a common you want to get to legendary, take a "eww, I didn't need _that_ item to proc flawless" item (AKA: fodder) close to the common's level (if you have spare gold, hunting the tradehouse with "flawless" and the right item level range as filters may also work.)
If you now fuse that wanted common and fodder flawless, there's about a 15% chance to turn the common into an epic and a 45-50% chance to turn it into a flawless. There's probably also a 15% chance of turning the fodder into an epic, but that's not as bad as it sounds and only loses 1 common of the wanted item.
I need lots of Legendary MoonBoots, MoonWalkers, NoblePlates, Winged Sandals for my efficient questing team.
Nice! Multiple targets and they are close-ish level (9, 15, 18, 22) so you can apply that for example
3x A+B+C fuses is much faster than A+A+A, B+B+B, C+C+C and both can average out to the same results.
So even with all the same quality items, we can save fuse time.
Moon Walkers + Noble Plate + Winged Sandals should fit into 1 cauldron for great and up, Moon Boots + Moon Walkers probably also just fit into one cauldron. (if levels are too far apart, fuse time goes up again)
I'm not a risk taker and my cauldron time is more important to me than materials, so I myself always do "100%" fuses up to legendary, which is probably why I didn't think of 3x great+flawless, which is only 92% and seems to be a quite slow fuse.
I think I did a mix of common+flawless and great1+great2+great3 fuses for my low level skilled items, then, if available, used any fodder failed to epic from the C+Fs to do a 4x flawless+fodder epic fuse (2-4 different flawless to speed it up further)  or if no fodder was available a plain 5x flawless fuse (2-5 different) and after that 4E+fodder legendary (if available) for legendary/mythical or 5E if no legendary fodder available. (again, mixing as much as possible to speedup as much as possible, while still averaging out to similar results if I didn't.)
There's of course the fusion calculators at viewtopic.php?f=6&t=7095
to try out fusions and see all the numbers that the game interface has no room to show.
 good chance you save 1 flawless at the cost of some fodder to getting an epic compared to 5x flawless, small chance you get a legendary straightaway.
as of 2016-09-11: Player level: 44, City: Eolythes, Blueprints: 517, Mastered: 419, Crafted: 78.61K
(except for tier 1 and some tier 2 artifacts mostly running my shop/gearing self sufficient)