First, Mr. S's point about kokyu is extremely important, and cannot be neglected. Eventually, the feeling *should* be like the saying in Daito ryu...the attacker's balance is taken upon contact.
That being said...
Im having issues with Shihonage in general, but I can pin point it.
It seems that its at the point that ukes arms cross my head...Im either raising his hands up or standing up to high, etc. (My body isnt in sync I guess.)
Practice keeping your hands just in front of your fore head...you should be able to watch your hands throughout the turn and cut. If you lose sight of your hands, you are giving uke their posture back.