I have created a tutorial covering the process of lightmap creation for UE4. The tutorial uses 3DS Max and UE4 4.7.3 however the content is applicable to any 3d package.
Hope this helps anyone looking to improve lighting quality in their projects.
@hobbitjack: great stuff! Glad to hear it I hope you get something out of the tutorial for your projects
@Noxxsan: the main reason is control, the automatic feature is ok and does a reasonable job sometimes. With the technique in the video you get control over the lightmap UV’s and can control the quality. I personally feel it’s better practice to do them manually as having control over this kind of thing is critical in my eyes as automatic systems will only take you so far. Hope this helps!