Distinguish between Problems and Constraints

You should not confuse problems with constraints.  A problem is something that can potentially be fixed, while a constraint is something that cannot immediately be fixed and within which you will have to work.  Once you've identified your constraints, don't waste energy fighting against them.  Acknowledge them and move on.

If management has hired you to solve a particular problem, and your analysis reveals that one of the major obstacles to success is management's resistance to change, that is a constraint rather than a problem.  Management will never conclude that it should fire itself, and management conservatism is a limitation within which you must work.

Time and Money Are Always Limited

Ever wish you had more time or money to devote to a project?  Writers in particular must be able to accept limitations.  If you write proposals, for example, you will always have a deadline.

If you have a proposal due at five o'clock, you must plan to complete the task in time to meet the deadline.  You could make it a lot better if you had just two more hours to work on it, but you may not have those two hours.  Hence, before you correct the punctuation, it's critical to make sure all the important stuff is right.

You must also take into account the constraints of your budget.  If you plan on sending a marketing letter to 10,000 potential clients, sending an enclosure may affect the cost: the enclosure itself will cost money to produce, and the additional weight could increase the postage cost.

You Are Accountable

Remember that you are bound by company policy. You would not, for instance, send out a report that flatly contradicted a recommendation your company had recently made to another client.  Nor would you send out a letter agreeing to provide services that your company does not offer or does not wish to be involved in.

Your name and the firm's name are on your communication, so you are accountable for the content and professionalism of your message.

Format Can Be a Constraint

If a client demands that proposals be limited to two pages, you will have to find a way to present your ideas in two pages.

Or if your assignment is to describe all of your company's retirement products on a bookmark that will be mailed out in customers' monthly statements, you must find a way to express your thoughts in few words.