To work on a square blade and path at impact try this drill. Place a short 2" by 4" board on the ground along your target line.  Tee a golf ball inside the board, so when you address it with a golf club, the toe is about 1/2 inch from the board.  Place an additional golf ball inside and forward of the first one, so when you address the first one, the heel of the club misses it by a 1/2 inch. (refer to illustrations below).   

Try hitting the middle ball by the board while missing the board and the inside ball. If you hit the board, your swing path is off. If you hit the inside ball you're not making solid contact. 

If you hit only the middle ball you are on your way to consistent solid golf shots. The easiest way to check your path on the course is to look at your divot after a shot.   An ideal divot will travel along the direction of your target. If your divot points left or right of your target, the board drill will help straighten it out.