How to properly setup user/groups/permissions for a web server?

Hello,

I spent all day figuring this out, but without success, so hopefully I can get some help here:

I have Ubuntu 13.10 VPS server with nginx, PHP 5 and MariaDB installed.

I created custom system user (for example “myuser”) which I use for connecting through SFTP to my server. In my user home directory I created “public_html” dir for my web root.

What I am trying to accomplish is that if I copy my files through SFTP (or rsync as well) they will be working not only with my user, but also with the PHP/server.

For example if I install WP it has no permissions to write in files as I am the owner of them. (therefore cannot upload files, install themes, plugins etc.) However this is not a WP problem, but overall user/group/permission setup problem

I was playing around with directory sgid, umask, assigning myself to www-data etc. but cannot find the right way to do this. (without manually chmod my files)

For example on my ex-shared hosting I just uploaded a file where I am the owner and there is no problem with permissions. Running nginx/php under my user I consider as not secure.

Please help me with this issue - I need a stable and secure option.

P.S. I know I can chmod my files after I upload/create them, but this is not a solution as it is very time consuming/overhelming. I need to automate this process and I believe there is a proper solution.

Thank you.