Prashun, try this next time you are sawing DT's;
Chuck the piece in a vise. Back a carpenter square up to it, preferably a long one, then line it up so that you can use it to sight how perpendicular you are to the board. Once you sight that, line up wrist and elbow so that your forearm is exactly in line with the back of the saw. Last line up your angle before you start cutting.
Even if you are cutting a DT in 3/4" or 1" thick board it's no where near as accurate as having a 24" reference on the back of the board.
Bumbling forward into the unknown.