A pour-over will is only used when your estate plan is based around a living trust. If your plan included a living trust, it will also include a pour-over will.
Your living trust is the only beneficiary named in your pour-over will. Your actual beneficiaries and the details about how your assets are to be distributed are outlined in your living trust. Your pour-over will acts as a “safety net” to ensure that any assets not funded into your living trust while you were alive are transferred to your trust at your death.
Like a traditional will, a pour-over will is subject to probate process. As such you do not want to rely on your pour-over will to distribute your wealth. Your pour-over will is precautionary tool to make sure your assets are distributed as you intend.
The same execution procedures exist for pour-over wills as for normal wills - 2 witnesses, over the age of 18 who are not named beneficiaries or otherwise potential heirs to your estate.
Just as with a simple will based portfolio, guardians of your minor children are named in your pour-over will.