On a cold, rainy day take the ingredients for a luxury hot chocolate into the office - a good hot chocolate mix, squirty cream, chocolate sauce and marshmallows - and make everyone a cup to cheer them up.
Help a family in financial need by cooking them a meal, bringing them groceries, helping with DIY, giving them clothing, etc. Do it in a way that makes them feel good about receiving your gift.
Be kind to yourself by eating well. Be conscious of what you consume and your body will thank you for it.
Ordered more than you can eat at a restaurant? Even if you don't want it ask for a doggie bag and offer it to the first homeless person you see.
In good weather host a BBQ for people who don't have an outdoor space of their own to enjoy (like friends who live in flats).