Avoid callbacks hell, by creating service objects

season_ticket.rb

class SeasonTicket < ActiveRecord::Base
  # ...
  def order!
    self.price = calculate_price
    self.status = :ordered
    save!
    self
  end
  # ...
end

season_ticket_mailer.rb

class SeasonTicketMailer < ActionMailer::Base
  def ordered_notification(ticket)
    @ticket = ticket
    mail :to => @ticket.player_email, :subject => t("mailers.season_ticket....")
  end
end

season_ticket_orderer.rb

class SeasonTicketOrderer
  def initialize(ticket, notifiers = [])
    @ticket = ticket
    @notifiers = notifiers
  end

  def order!
    @ticket.order!
    @notifiers.each{ |notifier| notifier.notify(@ticket) }
  end
end

season_tickets_controller.rb

class SeasonTicketsController < ApplicationController
  # ...
  def create
    @season_ticket = SeasonTicket.new(params[:season_ticket])
    @season_ticket.player = current_customer

    @notifiers = [
        MailerNotifier.new(SeasonTicketMailer, :ordered_notification)
    ]

    if @season_ticket.valid?
      SeasonTicketOrderer.new(@season_ticket, @notifiers).order!
      notice_message
      redirect_to wnm_core.profile_path
    else
      # ...
    end
  end
end