Growth Splines

Growth Splines can (optionally) be utilized to control the length and direction of your fur shells.

See example workflows from Nvidia here

When generating growth splines, try to generate less than 5,000. In general, less is better for (editing) performance.
Some DCCs generate Nurbs Curves instead of Spline curves - NeoFur fully supports both!
Set spline segments to a low number (minimum of 3) - This is the only data used anyway, so this will speed up the process and give you a clearer idea of what is happening. Having tons of segments per Spline will not improve quality - only decrease your productivity.
Preview with "guides" in your software instead of hair geometry - This is a more accurate visualization of the data that will actually be utilized.

Make sure spline object and character mesh both have the same pivot when being exported.
Epic’s FBX implementation does not understand spline data currently - this is why we access the FBX file directly via the fur asset.
Skin pose can be an issue - you need your meshes skin-pose to match the splines position. If it doesn’t, the splines will be trying to influence the wrong areas of your mesh.

Make certain the pivot-point of your spline object and your mesh match! This is a common mistake
Use the "spline debug" checkbox feature on the NeoFur component, this will help you see your splines in the scene and figure out what may be wrong with them.
The expected pose of your splines should match the bind pose of your skeletal mesh, if you are using a skeletal mesh. An incorrect bind pose could cause issues.