What would be the best approach for upgrading project while keeping the customization and bug fixes?

I am going to use NOP while I'd have some customization and bug fixes on it, what would be the best approach to keep upgrading to newer NOP versions while also keeping my own customization?
I found this thread. Do you any other idea?

Hi
Here is some information on Branching

By Vincent Driessen  https://nvie.com/posts/a-successful-git-branching-model/

NOP commerce Instructions:

Production branch: master
Development branch: develop
Feature and issue branches: Should start with "feature" or "issue". It should be followed by issue ID (according to our Github issue list) and some friendly name (example, "multistore"). Finally, it should look like "feature-34-multistore" or "issue-35-paypal-redirection-bug"
Release branches: Should start with "release". It should be followed by version number (example, "3.00"). Finally, it should look like "release-3.00"

http://docs.nopcommerce.com/display/en/Working+with+source+code+and+contributions

Forum
https://www.nopcommerce.com/boards/t/40111/github-branching.aspx

other links
NOP 3.9 since Base release.
https://github.com/nopSolutions/nopCommerce/compare/release-3.90...develop

Hi Milade,

Move your customizations to plugins so that way you can easily upgrade the nopCommerce Project while still preserving your changes as plugin projects.

Hope this advice helps,
Bruce

create a custom folder in each of the projects name it starting with a z so it will appear last "zCustom"
write all your code in these folders
u can also add your own dependency register file for your services and and data
since most of the classes are partial u can use any class with in the project

part for the views u can place all files in the custom folders

name your controllers starting with a z as well "zCustomer" so the view will be placed last on the list

when upgrading clone the new project and drag and drop your custom folders and views (5 minutes)