Finding a financial planner that fits your budget doesn't mean you can sit back and let him or her do all the heavy lifting.

Consumer Reports recently engaged an investment professional to review the advice of several relatively low-cost financial planners including some from T. Rowe Price, the Vanguard Group and Charles Schwab. Robert Glovsky, president of Mintz Levin Financial Advisors, said that in each case, important considerations — like insurance plans or life expectancy — were either omitted or left unexplained.

Financial advisers should clearly explain how they calculate important variables such as the inflation rate, anticipated rate of return on your investments and your life expectancy. A conservative bias that underestimates the potential of your investments, for example, may have you working longer than necessary, while an aggressive estimate can have you retiring before you can afford it.

Advisers should be able to provide a sound basis for estimating these variables, like looking at the historic rates of return on the types of investments you have. Glovsky found that sometimes this information is readily available, but in many cases he had to make one or more calls to the planner.

Also, don't expect to get a so-called comprehensive life plan from low-cost providers. Glovsky found that some advisers neglected important factors like estate planning, saving for a child's college education and insurance. A comprehensive plan should address all of these.

Last, your financial plan should include steps to compensate for the unexpected. A debilitating illness, for example, can change your earning potential, and a market crash can lower the return on your investments. If such events occur, your planner should specify how long to defer retirement, by how much you need to increase your savings or if you should sell your home.

Sound financial planning will tell you what actions seem necessary, and under what circumstances.