If you are talking about a wealth tax, you avoid this by not being wealthy.  Sell your assets and spend the money if you don't want to pay it.  There are allowances to distribute wealth tax free, you should do this to family.  You also get tax breaks by giving money to charities or investing in certain business ventures.
If you are talking about capital gains tax, go to some fucked up third world country where there is no society and therefore no tax.

Taxes are good things.  I know it might not seem that way sometimes, but they are there for a reason.  Pay them.