Most people should have a will, but it's not always the most significant estate planning document.

You can transfer many typical household assets like retirement accounts simply by naming beneficiaries – and documents such as financial and medical powers of attorney can be more powerful in determining the outcome of an estate.

Still, having a poorly written or out-of-date will can be costly and derail an otherwise well-planned estate. Wills are also particularly important for individuals with dependent children; they are the best way to name guardians in the event both parents die.

Experts typically advise individuals get their basic estate planning documents in order around life events such as when they get married or buy a home – and revisit them regularly, especially around retirement time.

Keep reading to learn how to complete your will in 11 simple steps:

1. Find an estate planning attorney or use a do-it-yourself software program

Individuals or families with relatively simple financial situations may be able to use a reputable online software program to complete their wills. Some software programs to consider include:

• Quicken WillMaker & Trust
• Fabric
• LegalZoom

Many situations, however, require using an estate planning attorney. "There are so many rules that come into play," Patrick M. Simasko, elder law attorney in Mount Clemens, Michigan, says. "They can't make it to the lawyer or they go onto LegalZoom, which is great, and they prepare their own documents, go to a website, download the will or they download trusts or different forms. But they don't know how to fill them out right, sign them right, notarize them right, so they don't mean anything," he says.

Hiring an attorney to create basic estate planning documents may cost a few thousand dollars, while an online software program can cost $100 or less. Experts warn, however, that improperly prepared documents can be costly down the road.

2. Select beneficiaries

One common mistake people make when planning their estates is failing to name or update beneficiaries on key accounts outlined in their wills.

"What's listed on all of the bank accounts, the life insurance, the house, that controls what goes where," Simasko says. "The beneficiary listed supersedes the will, but often there's just no consistency."

3. Choose your executor

The executor of your will is responsible for carrying out your wishes. This person is often a family member or an outside individual who should be responsible and detail-oriented.

"If you have no children, no nephews or nieces, you can always name your attorney or CPA," Brian J. Decker, owner and founder of Decker Retirement Planning, says. "One big no-no is a corporate trustee because of the expense. They charge 1% of the estate every year even if they do nothing, and they require you to have all your assets with them, so it's a double-dip."

4. Choose a guardian for your children

If you have dependent children, it's essential to name a guardian in your will. You don't have to ask permission before naming someone, but it's a good idea to specify multiple guardians in case one isn't able to accept the responsibility.

5. Be specific about who gets what

One of the most time-consuming aspects of creating a will may be deciding which assets to include and determining who will receive what. Stanley Kon, co-founder and chairman of Ripsaw Wealth Tools in Colorado, says individuals should consider the types of assets they're allocating to heirs to help with decision-making and management.

"Grandchildren will have a very long-term investment horizon and have more risk tolerance than their children," Kon wrote in an email. "An educational fund will likely have a much shorter investment horizon with less risk tolerance. This process can be used to separate what amount you need to fund your expected remaining life from what you expect to provide beneficiaries and manage accordingly."

6. Be realistic about who gets what

Think practically about how you'll distribute your assets. The No. 1 reason children stop speaking after a parent's death, Decker says, is due to boilerplate language directing tangible assets, such as artwork or jewelry, to be divided equally among them.

"If you have three kids who all play the piano and have this boilerplate language, the first one is going to pick the Steinway," he says. "You can't divide tangible assets equally. You will have kids who have strained relationships after the estate is distributed because of this."

7. Attach a letter to your will

You can attach an explanatory letter to your will. It can serve as a personal way to say goodbye and also go into detail regarding certain wishes you outlined.

8. Sign your will properly

Incorrectly executing a will may lead to a judge deeming it invalid. Witnesses must sign your will, and in many states, they can't be people who stand to inherit. Your witnesses also must be at least 18 years old.

Ideally, they'll be people who are likely to be around when you aren't. If something goes wrong and a court contests your will, the judge may want to call a witness to testify. The number of witnesses a judge needs to call may also vary by state.

9. Store your will safely

Make sure someone you trust knows where to find your will as well as any other important papers and passwords to financial accounts. Consider storing the original copy in a fireproof safe.

In some cases, you can execute and store wills electronically. These electronic wills, or e-wills, are valid only if they meet certain requirements – they must be in text form, not audio or video, and meet state rules regarding whether witnesses are physically present or remote.

10. Review and update your will

Generally, you should update your will every five years, Daniel R. Bernard, partner at Twomey, Latham, Shea, Kelley, Dubin & Quartararo LLP in New York, says.

"Similar to getting your car's oil changed every three thousand miles, this doesn't always happen," Bernard wrote in an email. "Another good rule of thumb is, any time you have a major life event, the birth of a new child or grandchild, a divorce, or the death of a spouse or parent, for example, it is a good time to review your documents."

11. Add other estate planning documents

A will alone may not meet all of your estate planning needs.

Trusts, for example, are another estate planning tool that enable you to transfer assets when and how you want. There are many different types of trusts, but one of the most common is a testamentary trust, which you can create within your will to transfer assets after you die.

Other estate planning documents – such as a living will that communicates your desires for medical treatment or power of attorney that allows a third party to make financial and legal decisions for you – function in concert with your will and should be the next thing you tackle after you write your will.