Cant add loop cuts after few extrusions and bevels sometimes while modeling I run into a weird problem,I'm sure you do too.SO,what happens is that as I go modeling and add in  few loop cuts,extrude few faces and bevel the edge and push/pull the beveled edge outwards or inwards.The next time I wont be able to apply a loop cut to a face.You might say ok then use a select or knife tool then.Sure I can do that but the problem is what if I want to add the loop cut/new edge to the exact center of the respective face(the same way loop cut tool automatically does).Now you might say turn on edge length and use the select tool and "C" key to put at the exact center of the edge.Now the problem to do put edge this way at exact position can be really difficult sometime.So,is there a way to put the loop cut even it seems impossible? Thanks in advance.
During knife cut you can use the Ctrl key to cut at the middle of an edge.

This is true also for the edges just created by the knife itself:



During this knife cut, you have some information in the bottom bar (as for other operators).