Hello-

Someone asked how I make the ends of lines tapered and the message started to get long, so I decided to make a post here. Hopefully this can help life easier for someone who is getting into decorating parts. I'll show you a quick way to do this in Inkscape. If you don't care for details, here's the TLDR version:

1. Make a wide rounded rectangle and copy it
2. Make a path
3. Add the shape as a Pattern Along Path
4. Presto! You're done!

If that went too fast, read below for the nitty gritty:

What are we talking about? Inkscape gives you three ways to terminate a path: Butt, Round, & Square. These are shown in red, but what if you want an end like the pink line? You'll need to use a shape instead of a path. Inkscape makes this easy with a Path Effect called Pattern Along Path. To do this we need two things. You will need a path that needs to be tapered and a shape that will stretch along your path.

Step 1: Make the Shape

First we will make the shape that will stretch along your path. I like to make a rounded rectangle so that it's wider than it is long. You want it shaped like a sausage. To do this, use the Rectangle [R] tool to make a rectangle and then grab the circle handle in the upper right and pull it down until it stops half-way. Now copy your shape to the clipboard.

Step 2: Draw Your Desired Path

Draw your line where you want it to go. I like to use the Bezier [B] pen to trace a path. Think of this line as your bones.

Step 3: Open the Pattern Along Path Editor

Open the Path Effects toolbar (under the Path menu) [Ctrl+&]. Make sure your line is active and click the + button to add an effect. If it is greyed out, make sure that you have selected a path (not a group or an image) and that you have ONLY 1 selected.

[Pattern along path button]
Find the Pattern Along Path button or just search for it at the top and then give it a click.

4. Magic!
   

Under Pattern source you have four options. You will want to use Link to Path in Clipboard, which is the last button on the right... give it a click. Uh oh, we have a mess! Don't worry, it can look way worse than this. All we need is a few adjustments.

Now instead of working with a path we are working with a shape. Normally we want an empty fill and a colored stroke for our lines, but since this is now a shape, we need to reverse those. Remove the stroke and add a fill color. To do this, I like to use the color palette on the bottom. Clicking on a color will set the fill and Shift-clicking will set the stroke. You can hit the red X on the left to set the fill or stroke to None.

Now adjust the width until your line looks correct. This will vary depending on how you set up your pattern shape. Most likely you will have to reduce it. If you are using the Edit Paths by Nodes [N] tool there will be a white handle at the starting point of your path. You can edit the width directly on canvas with it.

5. Tweak It
   

Ok, now we get to the power of our sausage shape. To make your line taper pointer, shrink your rounded rectangle horizontally to make it more like a circle. To make your ends rounder, stretch out your rounded rectangle. Note that you needed to choose Link to Path in Clipboard for this to work at this point. Also, if you stretch your shape vertically it will affect the line width.

6. Set It
   When you are satisfied with your line shape, you can make it permanent by choosing Object to Path (under the Path menu) [Ctrl+Shift+C]. This is a good idea to do before combining paths together because Inkscape may flip out.

7. More Notes
   You can experiment with different shapes. Just realize that your shape will be drawn as it appears on screen from left to right onto your path from the first point you set to the last. Additionally, when you use the Bezier [B] pen tool you have a shape option that you can add straight away. This will automatically add the path effect for you with a static shape. You can still go in and edit the parameters in the Path Effects toolbar.

I hope this helps someone. Cheers!