Left handed player

If you don't have a lefty,try two things.  The first is what mjamja recommended - use your forehand from your backhand side as a drill to the other person's righty forehand and also let your opponent use their forehand from the backhand side against your forehand.  One of the higher level players who visits my club, at the beginning of every session, would do his hitting drill for all his strokes across the major points of the table for an hour at least once a week - forehand crosscourt (regular hitting), forehand down the line to the other person's forehand at the edges and middle of the table, forehand inside out from the backhand corner to the other backhand corner etc.  The same with the backhand as well.  As trivial as it might sound, it lets you understand better what adjustments you need to make to your stroke/footwork given where you are on the table and how the table interferes with your stroke.  Footwork is important, but equally important is being able to hit the ball once you get there.  Usually, at the 1700 level getting to the ball once and hitting one shot to right place ends the point in your favor when you are drawn wide.  Hitting it to the wrong spot also ends the point if the opponent can block it to where you are not.

The other is to find a good backhand player with a loop and let him play with the backhand from the forehand side.  The way the ball breaks simulates what a lefty does if the backhand player sidespins the ball.  Of course, that would mean that you would need to find a training partner, and you know how that can go...

Good luck!