Most of the people think that employee motivation is necessary for a better working environment, but they must think about the other way, "a better environment will make a motivated employee", think about the place where you spent a comparably large amount of our time which is your workplace your office for at least 9 hours to 10 12 14 hours, in that case how you will like that place to be? If the environment is not good you will not be motivated with motivational speeches or even increase in salary will not bring results.
The lesser will be the workplace restrictions the better will be the motivation, if a person spending 10 hours in office he will need space to speak, to laugh, to use mobile, to even play games on computer, it is necessary to keep him motivated and make him less stressful. But if you will put restriction on every thing they are doing they will be annoyed with it and start looking for new jobs where they can spent their time as they wish. Playing a game for a few minutes on the computer will not harm the business, but a less motivated employee will!
And if you are a boss and you are running a whole department, it is better to stay cheerful with your employees and team members rather than frowning every time you meet them. They will work better for you.
Make a personal connection with your team members, rather than keeping the boss-subordinate relation. A personal connection is however sometimes make things harder because its a two way relationship, but if you keep a slight bossy style, it will be beneficial for you and will help in motivation of the team.