The different types of Sit

 For the sit at my side, I use a treat and lure the head. If that doesn't work, I've seen people just grab the dog and slide it over. They do catch on, but I'd think that way would take longer. Try moving the treat away from you, so the butt gets closer, and DO NOT reward crooked sits, period.

As for the finish, better treats? Left about turns, so she gets used to going around? I taught Ena with left about turns, using the word finish. Emma just followed the cookie. 

 Haha, I have the EXACT problem with Nikon!  He had a beautiful "base position" (what they call the heel sit in SchH).  However, his front sit was rock-back and too far to start with.  So, we did all this work having him literally drive his nose into my crotch and sit with his front paws on my feet.  Now his recall sit is awesome, but when I ask for a side-sit he either looks at me with a head tilt, or swings halfway back to a front sit.  It's just one of those things that need a balance in training and lots of repetition.  We'll probably work the side sits along a fence or wall this week.  Also I just shorten my hand up on the lead, basically to the collar, so if he's against the wall he can't swing his butt out, and if my hand is that close to his head, I can use that to control the position of the head.

I was going to make a video of his obedience tomorrow....

 For the right finish (I think that's what you mean?) I teach it with a lure.  I start with something REALLY good in my right hand, lure the dog around back, switch it to my left hand behind my back, and finish it up.  Eventually the right hand waving to the right becomes a hand signal.