[manfre]

Instead of env conditionals, I strongly recommended feature/functionality conditionals or variables. E.g. var.create_s3 is better than var env == 'prod'

[baby_souffle]

+1 for this. Do as much as you can in modules and write each of your modules to have a simple enable or disable input.

[bloopernova]

I just wanted to clarify: are you referring to this pattern?

  module "cool_name" {
    count  = var.create_cool_name ? 1 : 0
  }

I've always wanted a simple enable/disable syntax for modules in tf.