This seems _bad_. But I've seen it ALOT.

template.rb

class Template < ActiveRecord::Base
  belongs_to :template_type

  def some_method
    if template_type == :type_1
      # do type one things
    elsif template_type == :type_2
      # do type two things
    else
      # something else
    end
  end
end

template_type.rb

class TemplateType < ActiveRecord::Base
  has_many :templates

  TYPES = [:type_1, :type_2, :type_3]
end

I'm going to flesh out both these examples more later...