The federal estate and gift tax rate for deaths in 2018 is 40%.

Yes. Here are some of the most popular:

• Tax-free gifts. You can give up to $15,000 per calendar year (in 2018) per recipient without paying gift tax. You can also pay someone's tuition or medical bills, or give to a charity, without paying gift tax on the amount. This reduces the size of your estate and the eventual estate tax bill.
• An AB trust, where spouses leave their property in trust for their children, but give the surviving spouse the right to use it for life. This keeps the second spouse's taxable estate half the size it would be if the property were left entirely to the surviving spouse. However, with the $11.2 million personal exemption (for deaths in 2018) and "portability" for spouses, AB trusts are unnecessary for most couples. See Nolo's article Tax-Saving AB (Bypass) Trusts for more on this type of trust.
• A "QTIP" trust, which enables couples to postpone estate taxes until the second spouse dies. However, with the current very high personal exemption and "portability" of exemptions for spouses, this type of trust is also often unnecessary.
• Charitable trusts, which involve making a sizable gift to a tax-exempt charity.
• Life insurance trusts, which let you take the value of life insurance proceeds out of your estate.

The federal gift and estate tax are really just one tax. The individual exemption amount applies to property you give away during life or leave at your death. In other words, you can transfer, either while you're living or at your death, up to $11.2 million of property tax-free for deaths in 2018. This exemption amount rises each year because it is indexed for inflation.

Most gifts are tax-free, which means they don't count against the personal exemption amount. Only gifts of more than $15,000 per year to any one person or noncharitable institution are taxable. Making gifts of $15,000 or less, however, can yield substantial estate tax savings if you keep at it for several years.

Some gifts are exempt from the gift/estate tax no matter what their amount. For example, if your spouse is a U.S. citizen, you can give your spouse an unlimited amount of property free of gift tax. A noncitizen spouse can receive up to $149,000. (This amount is also indexed for inflation.) Any property given to a tax-exempt charity avoids federal gift taxes, and money spent directly for someone's medical bills or school tuition is exempt as well.

Yes. Even if your estate isn't big enough to owe federal estate tax, the state may still take a bite.

State estate tax. Some states collect tax from estates that aren't big enough to owe any federal tax. The tax rate is generally far less than the federal estate tax rate.

For example, in Oregon, estates worth more than $1 million may owe state estate tax. Property left to a surviving spouse, however, is exempt from state estate tax, just as it is exempt from federal estate tax.

More information on each state's estate tax.

If your state imposes estate or inheritance taxes, there probably isn't much you can do. However, if you live in two states -- winter here, summer there -- your inheritors may save money if you can make your legal residence in a state that doesn't impose these taxes.

For a comprehensive guide to estate planning, get Plan Your Estate, by Denis Clifford (Nolo).

Most estates -- more than 99.5% -- don't. The federal government imposes estate tax at your death only if your taxable estate is worth more than $11.2 million (for deaths in 2018). Assets left to a surviving spouse (as long as the spouse is a U.S. citizen) pass free of estate tax, no matter what the value.