You control the trade federation to create a blockade over a relatively peaceful planet
Causing the two Jedi who are sent to resolve the situation to rescue the Queen from the planet and fly off but not without damaging their ship and landing on a desert planet
While on the planet they will meet a boy, remember him, he will be important shortly
After the blockade situation is resolved you will need to secretly order the construction of a clone army
While this is happening you will be manipulating the trade federation and other systems to defect under the leadership of your padawan, don't worry too much about him he won't last long
Anyway years will pass and that little boy will grow up into a man-teenage-thing. What you need to do now is try to kill the queen-senator-girl-woman thing
but you need to fail at killing her for the OVERALL plan to follow through
Make sure you have the boy protect her, alone, with no supervision whatsoever
And then have the war you have been planning escalate further while those two fall in love
Capture the boys master (one of the two Jedi we talked about earlier) and then watch as the boy goes to rescue him in his gallentry
-oh make note, the boy's mother needs to die in his arms and he should kill an entire village, this is optional of course but it will speed things along and the no parents thing is a must
After the rescue the clone army will save them and a bunch of Jedi will die yada yada yada
WAR
ALRIGHT we are almost done now
War will break out and go on a few years making this whiny Little bantha fodder into something closer to your final product
From here you need to make sure that he secretly married the girl and knocked her up. Also you are gonna want to plant some seeds in there making him desire power during this time but that shouldn't be too hard for a puppet master like you
Anyway
At this moment his life will be collapsing in on itself which is excellent
This will probably lead to him having some pretty screwed up visions and this is normal
Use these to plant more seeds that the council doesn't trust him, that your his only friend, and that his wife will die if he doesn't dawn some black leather and do the nasty with the darkside
Get yourself captured and have him kill your padawan/apprentice and bam he's yours
But he isn't done yet
Oh no no no
Make sure his master is gone again on some important mission and stress how he should have gone instead and how Jedi suck
Then casually let it slip that you may or may not be suuuuuper evil
He will react and tell the council but not before you tell him that you know how to keep the wifey alive
He will have a crisis of faith
Save you
and swear loyalty to you huzzah!
From here kill all the Jedi
Well not ALL the Jedi
Leave a few alive
Like a small green one and the master and a few others
Send your new apprentice to a lava planet to kill some dudes and "end a war" and sit back and enjoy the rest unfold
You might need to fight a little green dude in the meantime but that's not a big deal and is mostly cgi anyway
The master will trick the wife into finding the husband
The wife will get chocked out by your new apprentice but not die
He will fight his old master but lose and fall into a pit of lava
The wife will then die in childbirth and the rest is easy
Pick up your well done apprentice and begin a short surgery replacing all his limbs with cool robotics and give him an awesome mask and cape
Tell him he killed his wife in anger to break the last of his will in and bam wham Kazan you sir have a new and never before used
Darth Vader
And THATS how you build a Vader