If you were to draw on paper, you would have the option to use a ruler to draw straight lines. That is not the case when you use a graphic program. However, when you are working with PaintShop Pro, there is a simple way to draw those straight lines you need.
A simple trick
The Shift key is the secret to drawing straight lines. Using the tool you have, click on one end of the "line" you want to draw, hold the Shift key, and while still holding it, click on the other end of the "line". Then, you can let go of the Shift key.
With this trick, you can draw lines in any angle you want.
Using the Brush tool
This is the most common tool you can think of using to make straight lines.
While holding the Shift key for more than one click, you can get creative and draw longer continuous lines at any angle.
And since the Brush tool can have different settings, those will also be maintained all along that straight line. If you have a Step value of 100, you will see the dots appear separately, yet, in a straight line too.
The Eraser tool
Since the Eraser tool is just like the Brush tool, but in reverse, you can use the exact same trick to cut out in a straight line too.
And just like the Brush tool, if you change the Step value, you will get individual dots being erased, but still in a straight line.
The Picture Tubes
You can also use this straight line trick to draw picture tubes. Although many picture tubes don't need to be in a straight line, some directional tubes can give a great result when they are straight, as they can be used as edges or others.
Or this one too.
The Warp Brush tool
Although we might not think of using the Warp Brush tool to draw straight lines, it can be quite effective to create some unique designs, on a background that has different patterns. Here is an example of a gradient background.
Although you can still use this trick for just about any tool, you might find it just less useful than when using the Brush, the Eraser, and the Picture tube tools. But don't let that stop you. Experiment with other tools and you might find something you like.
If you want more tips like these, check out the book Tips and Tricks for PaintShop Pro.