The most common estate planning mistake may surprise you. ‘The mistake actually isn’t part of the will and trust,’ said Dan Prebish, head of life services events at Wells Fargo Advisors, based in St. Louis. ‘It actually has to do with beneficiary designation.’ Prebish said people sometimes fail to designate who will gain control of various assets upon one’s death. ‘It’s not uncommon to find that someone still had their ex-spouse named [as the one to receive control of the asset,]’ he added. He said the fix is easy. When changing the beneficiary on a retirement account, for example, the update is as simple as filling out a form. Prebish said communication with one’s heirs is key, given the uncomfortable nature of estate planning. ‘Surprises are what breeds hurt feelings and even litigation,’ he said. ‘Find a way to explain this to your children or heirs.’ He says the starting point to any successful estate plan is a will, which is a legal document that delineates which heirs are to receive which assets or properties you own. ‘Talk to a local attorney to draft a will,’ Prebish added. Scott Gamm reports from New York.