One-time binding syntax: In newer versions of Angular (v1.3.0-beta.10+), use the one-time binding syntax {{ ::value }} where it makes sense
// avoid
<h1>{{ vm.title }}</h1>
// recommended
<h1>{{ ::vm.title }}</h1>
Why? : Binding once removes the watcher from the scope's $$watchers array after the undefined variable becomes resolved, thus improving performance in each dirty-check
Consider $scope.$digest: Use $scope.$digest over $scope.$apply where it makes sense. Only child scopes will update
$scope.$digest();
Why? : $scope.$apply will call $rootScope.$digest, which causes the entire application $$watchers to dirty-check again. Using $scope.$digest will dirty check current and child scopes from the initiated $scope