diff --git a/lib/generators/rails_icons/initializer_generator.rb b/lib/generators/rails_icons/initializer_generator.rb
index bc7ca43..e42fcd4 100644
--- a/lib/generators/rails_icons/initializer_generator.rb
+++ b/lib/generators/rails_icons/initializer_generator.rb
@@ -1,7 +1,9 @@
 # frozen_string_literal: true
 
+require "rails_icons/base_generator"
+
 module RailsIcons
-  class InitializerGenerator < Rails::Generators::Base
+  class InitializerGenerator < RailsIcons::BaseGenerator
     source_root File.expand_path("templates", __dir__)
 
     desc "Create the Rails Icons initializer."
diff --git a/lib/generators/rails_icons/install_generator.rb b/lib/generators/rails_icons/install_generator.rb
index a35cd74..5e96ad8 100644
--- a/lib/generators/rails_icons/install_generator.rb
+++ b/lib/generators/rails_icons/install_generator.rb
@@ -1,7 +1,9 @@
 # frozen_string_literal: true
 
+require "rails_icons/base_generator"
+
 module RailsIcons
-  class InstallGenerator < Rails::Generators::Base
+  class InstallGenerator < RailsIcons::BaseGenerator
     source_root File.expand_path("templates", __dir__)
 
     desc "Install Rails Icons with the chosen libraries. This creates the configuration initializer and will sync the icons."
diff --git a/lib/generators/rails_icons/sync_generator.rb b/lib/generators/rails_icons/sync_generator.rb
index 7edb8cf..ec08201 100644
--- a/lib/generators/rails_icons/sync_generator.rb
+++ b/lib/generators/rails_icons/sync_generator.rb
@@ -1,20 +1,17 @@
 # frozen_string_literal: true
 
+require "rails_icons/base_generator"
 require "rails_icons/sync/engine"
 
 module RailsIcons
-  class SyncGenerator < Rails::Generators::Base
+  class SyncGenerator < RailsIcons::BaseGenerator
     source_root File.expand_path("templates", __dir__)
 
     desc "Sync the chosen icon libraries from their respective git repos."
 
     class_option :libraries, type: :array, default: [], desc: "Choose libraries (#{RailsIcons.libraries.keys.join("/")})"
 
-    def sync_icons
-      raise "[Rails Icons] Not a valid library" if libraries.empty?
-
-      libraries.each { Sync::Engine.new(_1).sync }
-    end
+    def sync_icons = libraries.each { Sync::Engine.new(_1).sync }
 
     private
 
diff --git a/lib/rails_icons/base_generator.rb b/lib/rails_icons/base_generator.rb
new file mode 100644
index 0000000..64b91bd
--- /dev/null
+++ b/lib/rails_icons/base_generator.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module RailsIcons
+  class BaseGenerator < Rails::Generators::Base
+    def initialize(*arguments)
+      super(*arguments)
+
+      validate!
+    end
+
+    private
+
+    def validate!
+      raise RailsIcons::LibraryNotFound.new("") if options.libraries.empty?
+      raise RailsIcons::LibraryNotFound.new(invalid_libraries.join(", ")) if invalid_libraries.any?
+    end
+
+    def invalid_libraries = options.libraries.map(&:to_sym).map(&:downcase).reject { RailsIcons.libraries.key?(_1) }
+  end
+end
diff --git a/lib/rails_icons/errors.rb b/lib/rails_icons/errors.rb
index 20b16a4..020088b 100644
--- a/lib/rails_icons/errors.rb
+++ b/lib/rails_icons/errors.rb
@@ -1,5 +1,19 @@
 # frozen_string_literal: true
 
 module RailsIcons
-  class NotFound < StandardError; end
+  class IconNotFound < StandardError
+    def initialize(icon_name)
+      super("The icon `#{icon_name}` is not available. Please check the icon name and try again.")
+    end
+  end
+
+  class LibraryNotFound < StandardError
+    def initialize(library_name)
+      if library_name.empty?
+        super("No libraries were specified. Please choose from: #{RailsIcons.libraries.keys.to_sentence(last_word_connector: " or ")}")
+      else
+        super("The library `#{library_name}` is not available. Please check the library name and try again.")
+      end
+    end
+  end
 end
diff --git a/lib/rails_icons/icon.rb b/lib/rails_icons/icon.rb
index 662aed3..667f403 100644
--- a/lib/rails_icons/icon.rb
+++ b/lib/rails_icons/icon.rb
@@ -10,7 +10,7 @@ def initialize(name:, library:, arguments:, variant: nil)
   end
 
   def svg
-    raise RailsIcons::NotFound, error_message unless File.exist?(file_path)
+    raise RailsIcons::IconNotFound, error_message unless File.exist?(file_path)
 
     Nokogiri::HTML::DocumentFragment.parse(File.read(file_path))
       .at_css("svg")
diff --git a/lib/rails_icons/icon/file_path.rb b/lib/rails_icons/icon/file_path.rb
index d1061ae..3e481e2 100644
--- a/lib/rails_icons/icon/file_path.rb
+++ b/lib/rails_icons/icon/file_path.rb
@@ -13,7 +13,7 @@ def call
 
         icon_path = icons_path_in_app || icons_path_in_engines
 
-        raise RailsIcons::NotFound if icon_path.nil?
+        raise RailsIcons::IconNotFound if icon_path.nil?
 
         icon_path
       end
diff --git a/lib/rails_icons/sync/engine.rb b/lib/rails_icons/sync/engine.rb
index 19b5a4a..25f0693 100644
--- a/lib/rails_icons/sync/engine.rb
+++ b/lib/rails_icons/sync/engine.rb
@@ -37,7 +37,7 @@ def sync
       def clone_repository
         raise "[Rails Icons] Failed to clone repository" unless system("git clone '#{@library[:url]}' '#{@temp_directory}'")
 
-        say "'#{@name}' repository cloned successfully."
+        say "[Rails Icons] '#{@name}' repository cloned successfully."
       end
 
       def process_variants = Sync::ProcessVariants.new(@temp_directory, @name, @library).process
diff --git a/test/generators/initializer_generator_test.rb b/test/generators/initializer_generator_test.rb
index 7dfd2cc..eaac5c8 100644
--- a/test/generators/initializer_generator_test.rb
+++ b/test/generators/initializer_generator_test.rb
@@ -10,12 +10,21 @@ class InitializerGeneratorTest < Rails::Generators::TestCase
 
   setup :prepare_destination
 
-  test "generator creates the initializer with default library" do
-    run_generator
+  test "generator creates the initializer with Boxicons library" do
+    run_generator %w[--libraries=boxicons]
 
     assert_file "config/initializers/rails_icons.rb" do |file|
-      refute_match "heroicons", file
-      refute_match "tabler", file
+      assert_match "# Override Boxicons defaults", file
+      refute_match "Heroicons", file
+    end
+  end
+
+  test "generator creates the initializer with Feather library" do
+    run_generator %w[--libraries=feather]
+
+    assert_file "config/initializers/rails_icons.rb" do |file|
+      assert_match "# Override Feather defaults", file
+      refute_match "Tabler", file
     end
   end
 
@@ -28,7 +37,7 @@ class InitializerGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  test "generator creates the initializer with lucide library" do
+  test "generator creates the initializer with Lucide library" do
     run_generator %w[--libraries=lucide]
 
     assert_file "config/initializers/rails_icons.rb" do |file|
@@ -37,7 +46,7 @@ class InitializerGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  test "generator creates the initializer with phosphor library" do
+  test "generator creates the initializer with Phosphor library" do
     run_generator %w[--libraries=phosphor]
 
     assert_file "config/initializers/rails_icons.rb" do |file|
@@ -46,7 +55,7 @@ class InitializerGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  test "generator creates the initializer with tabler library" do
+  test "generator creates the initializer with Tabler library" do
     run_generator %w[--libraries=tabler]
 
     assert_file "config/initializers/rails_icons.rb" do |file|
@@ -64,4 +73,12 @@ class InitializerGeneratorTest < Rails::Generators::TestCase
       refute_match "heroicons", file
     end
   end
+
+  test "generator raise RailsIcons::LibraryNotFound when no library is specified" do
+    assert_raises(RailsIcons::LibraryNotFound) do
+      run_generator
+    end
+
+    assert_no_file "config/initializers/rails_icons.rb"
+  end
 end