I have three somewhat trivial tricks that seem to make those days a little brighter.
1. Fresh flowers
I picked this up from Apartment therapy's January Cure series a few years ago. There is something about fresh flowers that perk up your surroundings and remind you of life. If you want the feeling to stay even when the flowers are not in your eyeline pick scented flowers for instance lilac, roses and jasmine.
2. A moment of stillness
Essentially anything that gives you some mental stillness away from your worries and taking some time to switch off. Whether it is sitting with a good book and escaping, having a bubble bath, going for a coffee, meditation or going for run, this is about finding that allows you to reboot and refresh.
3. Cooking
It doesn't have to be anything fancy but the achievement of making something from scratch bolsters my day. If your in the need of serious therapy anything chocolate will do particularly my Artisan brownies and Mama Wilson's chocolate fudge pudding.