Hard surface modeling - Knife So what to do. I have a problem with topology. I'm still getting used to a 3D way of thinking. I was fixing topology on the other side of the knife, dissolving edges to keep the shape smooth (deleting part of the loop cut). The problem occurs when I have a transition from smooth to not so smooth :D. 



If it's possible draw the lines on how to retopology my knife.
The Subdivision Surface modifier (which it looks like you are using) smoothes the object based on the average of the points. So in order to make a crease look sharper, add more geometry there. You can do this with a loop cut by using CtrlR. There are also many other ways.

But then again, as mentioned by @RobinBetts, it is much easier to make the handle and blade separately, apply the modifiers, and then join them together.