Create simple ascend / descend points in your levels where players can move directly up or down. The animation isn't great and looks a bit stupid, but it's the one I thought looked best!
Simply install to your project:
sampctl package install Southclaws/samp-ladders
Include in your code and begin using the library:
#include <ladders>
To test, simply run the package:
sampctl package run
And connect to localhost:7777
to test.