I built our boys matching twin sized headboard based on the reclaimed headboard plan. I added some height to the headboard to account for the lights (to avoid them smacking their head on the light) but that's about it. You can read more about the beds here:
The build time was ridiculously quick. I just measured once, set the guide for the saw and cut both sets of all the pieces. The majority of the time was waiting for the poly to dry in the basement. It was a bit too chilly and damp I think, but eventually it dried.