I seem to be experiencing difficuly stimulating my outer pecs especially the lower outer pecs.

I cannot seem to develop that seperation between my outer pecs and my lats...the serratus muscle (which seperates the two) is hard for me to target and stimulate as well (I know this muscle is key in providing seperation)

Here is what I have already tried and continue to try doing...
Dips
BD and Cable Flyes
BB Rowes
DB Pullovers.

Now I should say that it does not look terribly bad...but that has always been an area of frustration for me. I have read some time ago that some muscles have may have smaller nerve ending which reduces stimulation or casues one difficulty to find that mind muscle connection to that area of the body.

Would appreaciate some thought and ideas on what could be done about this...if anything at all.

Thanks TC!