A properly structured estate should provide ample access to assets needed while you are alive without compromising your overall estate and legacy plans. While certain assets may be directly owned by your or your spouse, it is wise to make certain that other assets are safely outside your estate for estate tax purposes. Some assets such as business interests and investment portfolios and retirement accounts will require you to maintain direct control, while other assets such as life insurance may be outside of the estate in a properly structured trust.
Of course, estate tax planning is only one aspect of planning. Incapacity issues, protecting financially imprudent heirs, asset protection, avoiding probate, and minimizing income taxes are all other aims that can be achieved with proper estate planning.