These are my go-to dependencies for a new Rails project

Gemfile

source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }

ruby '2.5.7'

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '~> 6.0.2'
# Use Puma as the app server
gem 'puma', '~> 4.1'
# Use SCSS for stylesheets
gem 'sass-rails', '>= 6'
# Transpile app-like JavaScript. Read more: https://github.com/rails/webpacker
gem 'webpacker', '~> 4.0'
# Turbolinks makes navigating your web application faster. Read more: https://github.com/turbolinks/turbolinks
gem 'turbolinks', '~> 5'
# Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
gem 'jbuilder', '~> 2.7'
# Use Redis adapter to run Action Cable in production
# gem 'redis', '~> 4.0'
# Use Active Model has_secure_password
# gem 'bcrypt', '~> 3.1.7'

# Use Active Storage variant
# gem 'image_processing', '~> 1.2'

# Reduces boot times through caching; required in config/boot.rb
gem 'bootsnap', '>= 1.4.2', require: false

# MY ADDITIONS...

# Authentication: https://github.com/heartcombo/devise
gem 'devise'
# HTTP client (if you're making API requests, etc): https://github.com/lostisland/faraday
gem 'faraday'
# Use postgresql for production (default config uses sqlite)
gem 'pg' # postgres
# Slim syntax for templates: https://github.com/slim-template/slim-rails
gem 'slim-rails'

group :development, :test do
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
  gem 'factory_bot_rails'
  gem 'rspec-rails'
  # Use sqlite3 for testing/development... if you want to be lazy
  gem 'sqlite3', '~> 1.4'
end

group :development do
  # Access an interactive console on exception pages or by calling 'console' anywhere in the code.
  gem 'web-console', '>= 3.3.0'
  gem 'listen', '>= 3.0.5', '< 3.2'
  # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
  gem 'spring'
  gem 'spring-watcher-listen', '~> 2.0.0'
end

group :test do
  # Adds support for Capybara system testing and selenium driver
  gem 'capybara', '>= 2.15'
  gem 'selenium-webdriver'
  # Easy installation and use of web drivers to run system tests with browsers
  gem 'webdrivers'
  # Tool for testing time/date logic: https://github.com/travisjeffery/timecop
  gem 'timecop'
end

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]

#######################
### Installation... ###
#######################

# 1. Install the gems
# $ bundle install

# 2. Install devise
# $ rails generate devise:install
# Follow instructions in the console
# $ rails g devise:views
# Optional: Convert views to Slim: https://github.com/heartcombo/devise/wiki/How-To:-Create-Haml-and-Slim-Views
# $ rails generate devise User
# Optional: Update migration to add certain features
# $ $ rails db:migrate

# 3. Install rspec
# $ rails generate rspec:install
# require syntax config

# 4. Install factory_bot
# require helpers...