A lot of retirees and others are in the dark about annuities.

At their most basic level, annuities are simply insurance contracts for guaranteed income. They can be useful tools for securing financial well being, especially for those in or planning for retirement. But they are complex, which makes them prone to being missold by pushy insurance agents.

There are 15 or more types of annuities, and they’re complicated. Most people, including insurance agents, don’t understand them, said Stan The Annuity Man Haithcock, who incorporates a consumer advocacy element in his annuity sales business.

Annuity gurus urge consumers to follow these eight tips when shopping for annuities:

• Shop around. One size does not fit all, Haithcock says. Think through your needs. Then buy only an annuity that provides what you want. If you buy an annuity with lots of bells and whistles, you’re wasting your money.

• Be careful concerning variable annuities. Variable annuities consist of an insurance policy wrapped around mutual funds. Don’t buy one because its mutual funds offer possible growth.

If you want growth, buy funds directly, Haithcock said. It’s almost certain to cost you less for the same amount of growth.

Then buy a simpler, less expensive annuity that provides just the benefit such as lifetime income that you need, at less cost, he says.

• Buy only from financially sturdy insurers. Don’t buy from one whose rating is below investment grade from such rating agencies as A.M. Best, even if the price is better. A good upfront price doesn’t do you any good if the insurer folds, said Andrew Murdoch, president of Somerset Wealth Strategies, Portland, Ore. Try to stay with ratings of B or better, he says.

• Consider your overall finances. Don’t buy more of an annuity than you need. Make sure an annuity will jibe with the rest of your portfolio. Limit your annuity income to whatever you need that wouldn’t be provided by bonds and dividend stocks you already own.

• Strategize. If you have a single-life traditional pension, only consider annuities whose payments start when the pension beneficiary dies, unless you need more income sooner. Otherwise, you’re overpaying, Murdoch said.

• Ask questions. Quiz any agent you’re considering doing business with. Make sure you understand what an annuity will do, starting when, ending when, and at what cost.

Ask the agent to spell out all of the fees for upfront costs, annual expenses for the policy and any mutual funds, and for surrender charges, transfers and so on, Murdoch said.

• Understand an annuity’s terms. Many annuities base their payments on a so-called guaranteed value. That can be much higher than the policy’s actual value. Many policies used to base income on a peak guaranteed value, even if it later declined. Not anymore.

Be sure you understand which value payments and other benefits are based on income can be based on one, while other benefits can be based on the other and whether they are based on peak value or current value.

• Watch out for excess withdrawals. A policy’s fine print may allow the insurer to cut the guaranteed value that income payments are based on if you withdraw more than allowed yearly. That forces the income payouts themselves to decline.