While doing so you must ensure two things. First and foremost, the wallpaper that you put on must not be offensive in nature. Secondly, the colleague whose wallpaper you are changing must be someone who is cool with the idea of pranking. Do not go for someone who is easily offended.
One of the best ways to lighten your mood at work is by
having a cordial relationship with your colleagues. The best way to build such
a relationship is to engage in fun activities together. Now we understand that
it may not be possible for you to engage in such fun activities during working
hours.
Most of the times the goals or targets that your boss sets
out for you are long term in nature. To lighten your mood, what you can do is
to break up those goals into a number of small ones. Each time you achieve a
goal you can applaud yourself and treat yourself to something nice.
