Go to your mouse control panel and turn on mouse trails. Adjust the trail length to the maximum.

Now to back to your drawing program and without actually pressing the draw button (With a pen just hover above the canvas) and use the mouse trails to previsualize your strokes.

For example to draw an elipse just practice it and look at the trails, as soon as you have the major and minor axis’s down, gently press to draw.

Need to draw a perfect line to connect 2 points? Draw your fantom line in the air and press to draw when you have visualized it using the mouse trail.

My hit percentage went way up using this technique. It’s not cheating in my opinion because you do the same with pen and paper, it’s just that with a tablet your are disconnected from your drawing surface because you draw on the table/tablet instead of directly on the screen so you can’t do this as well. With mouse trails turned on you can.

Until one day a light-bulb went of… That plastic surface on the tablet that you rest your palm on is not paper. Paper is nice and slippery and absorbs the moisture from your hands. When your hands get just a little bit sweaty the plastic surface on the tablet will cause increased and random friction and that is what messes up your nice precise lines ellipsis and circles so they look all wrinkly and horrible.

Go out and buy a stack of those thin cotton gloves for ladies, silk is even better if you can afford them. Cut of the fingers and never mind looking like MJ hehe. You can try out the difference right now by getting a piece of paper and resting your palm on it, then slide around on the tablet surface. It will be quite easy to feel the difference.

Now your palm will slide with no friction on the tablet plastic and you can draw straight lines WAY better. For me it was like night and day so try it out.