What is a best practice when wanting to override a Bootstrap LESS file?

I have been working on multiple projects that are based on the Bootstrap theme in Drupal. I always make a sub-theme and I always get into the same “problem”. I need to customize my theme and I feel like I am always writing more code than I should.

My main issue is that I need to change code that is in my base theme: https://screencast.com/t/IwvPJ6Szn19

For example I would like to change things in the navbar.less from my base-theme. I would normally add the same number of classes so that my sub-theme less has a higher specificity. But when I need to change a variable from variables.less, I go in my sub-theme and add that variable again with my desired value in the variable-overrides.less file.

Is there a way to do this with my navbar.less? What is a best practice when wanting to override the less files from the Bootstrap base theme (forms.less, navbar.less, tables.less)?

Also what goes in the overrides.less in my sub-theme?