When you have a multi dog household it is important to make time to train each dog individually. Not only does it take away the distraction of the other dogs, but it builds up the bond that you have with each dog.
Not only is it important to train separately, I also recommend having time to play games separately, this again helps to strengthen the bond you have with that dog.
Time away from the other dogs on a regular basis, isn't just good for the bond you will develop, not just the improvement in being able to train but the confidence to cope without being with the other dogs. As heart breaking as it is to think about, one of my dogs is much older than my other two and he won't be around as long as they will, and I would never want to put either of my younger dogs in a position where they have only ever been with the older dog and therefore when he goes, they become broken.
When you are having 1 on 1 sessions, it is really important the other dogs don't become stressed and worked up over the other dog been taken away. I often give them a Kong, or a chew or something to keep them occupied while I work with the other dog, this means when the other dog isn't around, they are getting on with something fun and tasty.
Dog training should always be fun for dog and owner.