My favourite little luxuries for when I need a boost are Starbucks Caramel Hot Chocolate (or any hot chocolate really *g*), a long bath with bubbles or a bath bomb and flowers (the brightest colours you can find, and often if you can find a florist near the end of their day you can get bigger bunches cheaper, as a student I used to buy bright yellow spider carnations from the supermarket everytime I had an exam or a particularly nasty seminar and I found it was the best £2 pick-me-up)