Basics to cut-join a video without re-encoding using I,P,B frames

I cut a large mp4 file into several small parts and later join them together using joiner software. I know that every parts have to start from a I-frame but what type of frame should I choose as end? B, P or I?
For example- a video frame is like IPBBPBBPI... which frame should be the last?

Thanks WHS for your reply. So you mean end point can be any frame, no difference, right? Sometimes a glitch like overlapping, shakiness remains in that joining position that's what worries me. And what do you mean by a trailer?