EX1: you can give your wife unlimited assets without tax implications.
EX2: Let's say you and your wife have a 7 million$ 50% of which is appreciated assets, and 2 million in life insurgence and 3 children. Each of you can give 1 million to each child, so 6 million is exempt, as is all life insurgence thus only the last million is taxed at 45%. Resulting in a 0.450 / ( 7 + 2) = 5% effective tax rate.
Note: If they actually sold their appreciated assets they would pay more in taxes.
EX3: 1 billion in assets. Set's up a blind trust = zero direct taxes on death. Money can compound tax free in the trust and is only taxed on disbursement.
EX4: 1 billion donation to the red cross = zero tax.
PS: If you do nothing and leave 5million to 1 person the effective tax rate is still only 36%. You really have to have huge amount in assets and stupid tax advice for this to be a major issue.