Plan ahead, in the UK you have an allowance that you can give to someone per year, before your death, each year donate up to the amount in cash or share in property, year by year, this will limit the tax burden on you.
Obviously, make sure you've bought your children up well, and they wont fuck you over at old age, (and take your property and evict you))..
by the way in the UK we call it inheritance tax, and it isn't just at time of death, it applies at all times, technically if I buy my son a £13,000 car, my son is liable to pay inheritance tax on it, but this rarely happens because it not really accounted for properly (but maybe one day when everything becomes digital, uncle sam will be able to track passover of goods from one person to another and tax you on it).
After death obviously it's a bit more difficult to get away with because the taxman will come in and audit all your belongings etc.
Secondly, rich people dont pay as much tax as poor people (in proportion), ruich people can hire accounts and lawyers who will advise them of every legal tax loophole there is to avoid paying the taxman.
e.g. Company directors often get paid in shares in companies (which is taxed a lot less than hard currency payments)
With estate tax I'm sure there is a way to pool ownership, so say mum, dad, 2 kids all share ownership of the property, so when dad dies the tax burden is a lot less, because dad owned 25% of the £2M property.
