Neb,
First, all of the above...
But a question next, which way are you headed down? Looking at the cut with the stump in from of you, does it just slope down to the left, or does it slope down away from you?, or both.
Each saw of course has its own balance points, and correct bar lengths to be "balanced".
Lets assume you have a sharp and true chain and bar, and the bar is not over or undersized for the saw....
pick up the saw and hold it by the front handle so it lays sideways, like you're going to start a cut, now hold it with one hand (left) and play with where you hand sits on the handle to keep the bar level (even throw a carpenters level on the bar) by moving you hand back and forth on the handle you'll change the "angle of attack" get it set so it's level then imagine dogging the saw and manipulate the rear handle to swing the bar. Concentrate on what your left wrist is doing to ensure the bar stays level. Muscle memory that motion (repeat repeat repeat.) This part is really only needed for the first few seconds, but these are the most important, once the cut is set... it's set and you pretty much have to live with it, minor adjustments can be made, but they are minor.
Now on the next cut spend a few seconds balancing the bar out and remembering how to pivot the saw at the head without effecting the angle of the bar.
If the cut slopes down away from you after that, you're lifting the power head too much while you cut.. if it slopes down left, you twisting the saw (heaven forbid I said this next part!), don't use your left hand, only dog the saw and pivot it with you right hand keeping you fingures off the front handle, and let the saw do the work...
That's all I can suggest for now, with info given.
