I have a tough beard too. I used to use a Gilette Sensor (twin bladed) razor but I got sick of paying the extortionate
amounts of money they ask for new cartridges.
Now I use a single bladed safety razor. The secret I find is to use a good quality shaving soap, plenty of hot water
and work the lather well in before I set the steel to work.
Have a look at this guys videos http://uk.youtube.com/user/mantic59