Planning for what happens to your possessions and money after you die is more than just sobering. There are many decisions to make and lots of paperwork—which explains why most Americans don’t have even simple wills. But once you’ve made an estate plan, you’ll find it calming and reassuring to you and your family.

To compile basic dos and definite don’ts, we asked a dozen helpful estate-planning specialists to share their top strategies for saving hassles and money—and for their warnings about common mistakes.

The goal is to communicate your end-of-life healthcare wishes and document what you have and who gets it after you die. You’ll want the fastest and least costly way to transfer it to your heirs or charities, minimizing payouts to probate courts, attorneys, accountants, and Uncle Sam.

While some of us can do our own estate planning, most will need to hire an expert. We offer advice on that, too.