All folks give good advice here:

Practice with longer rods, ideally with med actions to train your brain and muscles to feel the rod loading
If you can afford it get into a casting school to avoid bad habits that are difficult to get rid off, if not some more experienced fly fisherman that can guide you along the way or you can also record yourself casting and then watch it to correct and iron things out
Practice and practice and practice at a back yard, and while you do it think and pay attention to your movements, specially the abrupt stop at the forward and the back cast

I put a double taper 4 wt line on the little Imperial and I can now feel the rod load!

try to get a heavier line or a shooting head