Christmas can be such a challenging or difficult time for many. I honestly think there are lots of people who are alone or unhappy at Christmas.
I havent got this all worked out yet but one year went better for me when I treated myself to a proper meal with trimmings within my budget instead of snacking.
Other things that come to mind are reading a new or favourite book. Purchasing a new Christmas cd or listening to a radio station...sometimes I like to listen to k-love.
Other gifts to self could include something new to wear that's super comfortable.
Ways to reach out for company or social connection can include stopping by forums, going to a church service even if not a regular, sending messages using whatsapp and calling up someone to wish them a happy christmas.
I think preparation helps a lot, so having a plan pencilled in that you look forward to as well as making the effort to send cards by mail a few weeks ahead can really make a difference.
If you really want to get out some charities do Christmas meals either to join in with or to help out at.
Also what would be a treat for your inner child??