There’ll be more detail here shortly, including a tutorial showing you how to use the Kreg Jig and Pocket Screws to speed the process of building baseboards from dimensional timber (lumber) or plywood.
A note on my not using MDF
Readers should note that while you certainly can build using MDF I do not advocate its use in layout baseboards purely from the weight perspective and its known moisture instability issues. I know that other layout builders have and do use it finding it to be stable over the longer term. Living in Ballarat where we have large temperature variations hot to cold and the reverse in short time periods (sometimes measuring in minutes) added to humidity variations between 10% and 100% within hours I’m concerned that MDF would become at best problematic.
Why I use pocket hole technology
Sure, fast and strong; It really is as simple as that.