It is my understanding that Celebrimbor forged the Three Rings of Power, and that Sauron had no part in the creation of those rings. So why is it he was able to control them. I thought that all the other rings were bound to his will because he instructed their craft. So how is it that the rings which Celebrimbor made, presumably due to his own craft, could be made thralls for Sauron?
Celebrimbor had been taught how to make Rings of Power by Sauron himself. Even though Sauron wasn't in the room when he made the Three, he was still using Sauron's techniques. Presumably, Sauron taught him to create rings in such a way that anything he produced was still subservient to the One Ring.
To use an analogy: Suppose I taught someone how to create a computer program, while secretly leaving in a innocuous-looking backdoor for myself. Even if my pupil created a lesser, slightly different program, I could still probably hack it, because I know everything about coding that they do. And since they don't know about the backdoor, they might even replicate it themselves.
Or think of it this way: do you honestly believe that Sauron could have taught his enemies how to create powerful magical weapons without some way of ensuring those weapons could never be used against him?
Sauron made the Ring specifically to control the others; it even says so on the Ring itself:
Three Rings for the Elven-kings under the sky, Seven for the Dwarf-lords in their halls of stone, Nine for Mortal Men doomed to die, One for the Dark Lord on his dark throne In the Land of Mordor where the Shadows lie. One Ring to rule them all, One Ring to find them, One Ring to bring them all and in the darkness bind them In the Land of Mordor where the Shadows lie.[emphasis on the Ring's enscription]
from The Silmarillion, Of the Rings of Power and the Third Age:
In those days the smiths of Ost-in-Edhil surpassed all that they had contrived before; and they took thought, and they made Rings of Power. But Sauron guided their labours, and he was aware of all that they did; for his desire was to set a bond upon the Elves and to bring them under his vigilance.
Now the Elves made many rings; but secretly Sauron made One Ring to rule all the others, and their power was bound up with it, to be subject wholly to it and to last only so long as it too should last...Therefore the Three remained unsullied, for they were forged by Celebrimbor alone, and the hand of Sauron had never touched them; yet they also were subject to the One. [emphasis mine]
and, in LOTR, Book I, Ch.2:
[Gandalf, to Frodo] ‘The Three, fairest of all, the Elf-lords hid from him, and his hand never touched them or sullied them. Seven the Dwarf-kings possessed, but three he has recovered, and the others the dragons have consumed. Nine he gave to Mortal Men, proud and great, and so ensnared them...So it is now: the Nine he has gathered to himself; the Seven also, or else they are destroyed. The Three are hidden still. But that no longer troubles him. He only needs the One; for he made that Ring himself, it is his, and he let a great part of his own former power pass into it, so that he could rule all the others. If he recovers it, then he will command them all again, wherever they be, even the Three, and all that has been wrought with them will be laid bare, and he will be stronger than ever. [emphasis mine]