OK I'm going to whole sale rip off the DDO forum for this one.
Once you hit level 3 of your first chosen fate - the bottom right box "twist of fate" is no longer greyed out - you will also see a "1" in the upper left hand corner of the Twist of Fate box.
Click the top fate box to use your first fate point to unlock Twist of Fate, and then every three levels you gain in any fate will provide you with another fate point.
Below is my rip off from the forums, which helped me quite a bit to understand who it works.
http://forums.ddo.com/showthread.php?t=381801
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lets say you've got a bard with a 2 level rogue splash, and you start in the fate singer destiny. As you're leveling up in the fate singer destiny you notice you've unlocked the magister destiny.
you notice that the magister destiny has an enhancement that boosts your refelex save by 2/4/6 you think it'd be really nice.
So you make the magister destiny your active destiny at the fate spinner, advance 3 ranks in that reflex save line.
you then drag the reflex save enhancement into your twist of fate box.
Then you switch back to fate singer.
You now keep that magister reflex save enhancement as well as everything you've unlocked within the fate spinner tree. You can change your twists at the fate spinner it just seems to cost plat.
(snip)
in the scenario listed above you lose all the fatesinger perks (unless you decide to twist one of those while lvling magister) but when you switch back to fatesinger after getting the twistable bonus from magister you regain everything that was already active in your fatesinger destiny.
In general, the twists of fate are great if you see perks you want from other trees that you want to lvl in said tree to get, for instance my artifacer at this time is leveling his fatesinger destiny so i can eventually get to the shadow dancer destiny. If say i wanted to keep some of the enhancements from my fatesinger tree i could spend the fate point I get as a lvl 3 fatesinger to unlock the first twist of fate spot then stick a tier 1 enhancement in it. This twisted enhancement will now stay active no matter what epic destiny i have active, though will be useless if i decide to continue leveling as a fatesinger as i have the enhancement as part of my active destiny.
(snip)
When you switch a destiny to level up a different one should not be done in a quest where you will need those abilities. If you are going to be doing a xp run in some quest where you feel you can do fine with the new destiny would be the time when you can afford to level up the new one. They are not saying to drop the current destiny willy-nilly, that would just be silly.
(snip)
short term loss for long term gain.
by twisting into magister temporarily i that fate singer permanently gains +6 reflex saves for as long as he wants to keep it in his twists of fate slot.
my paladin for example
has twisted the +6 umd you can get from fate singer
and the haste boost you can get from the fighter destiny
i didn't have access to all my cool unyielding sentinal stuff whilst i was unlocking those two enhancements for my twists of fate slot.
but now that i'm back in unyielding sentinal with no fail heal scrolls and haste boost it was totally worth it.
(snip)
A slot of Twist of Fate allows you to take one ability from another Destiny you leveled up in and have it as extra.
For example my Favored Soul leveled up as Exalted Angel, then at Exalted Angel 3 i unlocked 1 twist of fate and the adjacent destiny which is Unyielding Sentinel (Paladin type).
So I made this new Destiny active, I got 4 ranks in it, spend 4 points in 2 upgrades of "+20% fort, +1 saves" for a total of "+40% fort, +2 saves", then I put this ability in my Twist of Fate slot, switched back to Exalted Angel and voilà !
I'm now an Exalted Angel 3 with an extra 40% fort and 2 saves and I'm back to leveling Exalted Angel toward 4.
Once you hit level 3 of your first chosen fate - the bottom right box "twist of fate" is no longer greyed out - you will also see a "1" in the upper left hand corner of the Twist of Fate box.
Click the top fate box to use your first fate point to unlock Twist of Fate, and then every three levels you gain in any fate will provide you with another fate point.
Below is my rip off from the forums, which helped me quite a bit to understand who it works.
http://forums.ddo.com/showthread.php?t=381801
_______________________________________________________________
lets say you've got a bard with a 2 level rogue splash, and you start in the fate singer destiny. As you're leveling up in the fate singer destiny you notice you've unlocked the magister destiny.
you notice that the magister destiny has an enhancement that boosts your refelex save by 2/4/6 you think it'd be really nice.
So you make the magister destiny your active destiny at the fate spinner, advance 3 ranks in that reflex save line.
you then drag the reflex save enhancement into your twist of fate box.
Then you switch back to fate singer.
You now keep that magister reflex save enhancement as well as everything you've unlocked within the fate spinner tree. You can change your twists at the fate spinner it just seems to cost plat.
(snip)
in the scenario listed above you lose all the fatesinger perks (unless you decide to twist one of those while lvling magister) but when you switch back to fatesinger after getting the twistable bonus from magister you regain everything that was already active in your fatesinger destiny.
In general, the twists of fate are great if you see perks you want from other trees that you want to lvl in said tree to get, for instance my artifacer at this time is leveling his fatesinger destiny so i can eventually get to the shadow dancer destiny. If say i wanted to keep some of the enhancements from my fatesinger tree i could spend the fate point I get as a lvl 3 fatesinger to unlock the first twist of fate spot then stick a tier 1 enhancement in it. This twisted enhancement will now stay active no matter what epic destiny i have active, though will be useless if i decide to continue leveling as a fatesinger as i have the enhancement as part of my active destiny.
(snip)
When you switch a destiny to level up a different one should not be done in a quest where you will need those abilities. If you are going to be doing a xp run in some quest where you feel you can do fine with the new destiny would be the time when you can afford to level up the new one. They are not saying to drop the current destiny willy-nilly, that would just be silly.
(snip)
short term loss for long term gain.
by twisting into magister temporarily i that fate singer permanently gains +6 reflex saves for as long as he wants to keep it in his twists of fate slot.
my paladin for example
has twisted the +6 umd you can get from fate singer
and the haste boost you can get from the fighter destiny
i didn't have access to all my cool unyielding sentinal stuff whilst i was unlocking those two enhancements for my twists of fate slot.
but now that i'm back in unyielding sentinal with no fail heal scrolls and haste boost it was totally worth it.
(snip)
A slot of Twist of Fate allows you to take one ability from another Destiny you leveled up in and have it as extra.
For example my Favored Soul leveled up as Exalted Angel, then at Exalted Angel 3 i unlocked 1 twist of fate and the adjacent destiny which is Unyielding Sentinel (Paladin type).
So I made this new Destiny active, I got 4 ranks in it, spend 4 points in 2 upgrades of "+20% fort, +1 saves" for a total of "+40% fort, +2 saves", then I put this ability in my Twist of Fate slot, switched back to Exalted Angel and voilà !
I'm now an Exalted Angel 3 with an extra 40% fort and 2 saves and I'm back to leveling Exalted Angel toward 4.