Quick tip what not to do with a wooden fence post 

I just chuck them in and importantly slope the concrete away from the posts at the top - as you know, the area between post and ground level is where posts always rot. Slope the concrete, it will prolong the life of the post as you will know.

I used to add pea gravel to the bottom on the hole to help with drainage but as 90% post rot from the top I stopped.

Nice editing at the start of the vid 👌