Deciding what to put into a Last Will and Testament is a VERY individual choice! We prepare wills that are a few pages long, and also wills that are like a booklet. And the difference is not always how much money and property that the client has.
So, how specific should you be?
Generally, we advise against putting in provisions that may make it difficult for your Executor to do his or her job.
So, the first order of business is to name an Executor whom you trust. This person will be your personal representative in distributing your estate after you are gone.
Your Executor has to do what is best for the estate but also has to follow your wishes as closely as possible. If you trust your Executor and are willing to let him/her make decisions, then you don't have to be as specific. You can let go of the "control" and just allow the person that you have chosen to do his/her job, depending on what is best for the estate at the time. You don't have to say, "My Executor must put my house up for sale within 30 days of my death", you can allow him/her to place it on the market at the time that is best.
Usually, making a long list of each and every item that you own and insisting that it goes to a certain person doesn't work well. What if the person doesn't want that item, but they prefer something else? What if you no longer own the item when you die, or if the item is not in good condition? What if it costs a fortune to ship? Much better to allow your Executor to have the authority to distribute things, if possible. (with the exception of certain family heirlooms, of course.)
The second piece of advice is to avoid putting "contingencies" into your will. ("I leave my son my home if he is married and has children.", "I want my grandchildren to have my boat if they live in Texas, but if they live in another state, then I want them to have my oil paintings."). These types of statements only make it more difficult to administer your will. My advice is to leave out the "if ... only" statements altogether.
The third piece of advice is to make sure that you don't have any conflicts between your will and other legal documents. For example, if your will says that you leave a retirement account to your son, but the beneficiary designation says that you leave it to your daughter, that sets up a conflict between them, confusion, and extra time in getting it sorted out. (By the way, the beneficiary designation to an account generally rules, as long as it is accurate and properly done.).
Tip number four: Avoid confusion by updating when necessary. If you have gotten a divorce or are separated and not living with your spouse, make a new will and take that spouse's name out. If the relationship between you and a person who has a major role in your will has changed, update your will. Do you really want that cousin that you have been angry with for years to be the one making decisions that affect your estate and its distribution?
There is a lot to be said for "keeping it simple". Simple, yet clear is the best way to go when at all possible.
Family Law, Wills, Powers of Attorney & Estate Planning