http://www.pathf.com/blogs/ruby-and-rails-style-guide/

style.rb

# Class methods
YAML.load()
YAML::load()

# Array and Hash
array = Array.new
array = []

hash = Hash.new
hash = {}

# variables
# a)
x = 0
y = 0
z = 0

# b)
x = 0; y = 0, z = 0

# c)
x = y = z = 0

# synonyms
# although I acknowledge "size" and "length" are not always synonyms, 
# but in most cases, they are.
"hello".size
"hello".length 

# how to return nil
# a)
def do_somehting
  # Cool code here.
  rescure
  return nil
end

# b)
def do_somehting
  # Cool code here.
  rescure
  nil
end

# c)
def do_somehting
  # Cool code here.
  rescure
end