The culture and spirit of your team is particularly important. In fact, many times I will state that culture is everything. Good culture can drive your team and make the job enjoyable.
Bad culture can destroy a team quickly or destroy it slowly based upon the degree of what is making it bad. Therefore, back to my statement. Culture is everything!
There are many things that help drive a good culture. Building upon the right values is the start that then defines your mission and vision of your organization. Living those values daily is also particularly important.
The additional item I encourage, teach, and do myself is to not be afraid of embarrassing yourself. We do this by creating ways to have fun that adds to our environment. For employee meetings we have presented skits, sang songs, and even soaked someone with a super soaker so everyone could laugh and enjoy.
The culture you create is a team that looks forward to the next meeting or the next time you will do something funny. Weaving in a message for business becomes easy and the buy-in from everyone becomes contagious.
Being a professional does not mean you cannot be silly.