Misc

Trust Proxies Middleware *
$listeners On EventServiceProvider *
Blade::if() *
Notification::route()->notify()

Routes & Rendering

React Preset / None Preset
Route::view *
Route::redirect *
Returning Mailables From Routes *
Renderable Exceptions (And Report Method) *
Responsable Interface *

Validation

Custom Validation Rules (make:rule) *
->validate Returns Validated Data *
$request->validate() Method *

Testing

Migrate Fresh & Testing Flow Improvements *
Separate Model Factories By Default, make:factory Method
withoutExceptionHandling In Tests *

Packages

Package Auto-Discovery *
Vendor Publish Selection Menu *

Queues

Job Chaining *
deleteWhenMissingModels For Missing Models On Job Injection
Horizon
Pivot Casting - https://laravel-news.com/laravel-5-5-pivot-casting
Cache Locks (Memcached + Redis) *?
JSON Exception Messages When Request Wants JSON
User ID & Email Address In Logs If Possible
Change Format Of Validation Errors In One Spot
make:model -a
Fluent Resource Options (https://github.com/laravel/framework/pull/18767)