The amount of money you should give to your doorman for Christmas depends on a few factors, such as your financial situation and your relationship with the doorman. If you have a strong relationship with the doorman and are able to afford it, you might consider giving them a more generous gift such as a gift card or cash. However, if you are not able to afford such a gift, it's perfectly okay to give them a smaller token of appreciation, such as a small holiday-themed gift basket or a homemade treat. Ultimately, it's the thought that counts and the doorman will appreciate any gesture of kindness you make.