The answer to the question is going to differ widely depending on the country in question.

Denmark for example would be pretty much the same as before the Nazis occupation. The Danes didn't really resist German occupation and as a result the civilian government was left in power and the population was able to go about their day to day lives. The Danish government even did a good job of defending its Jewish population and was able to save many of them. This all changed in 1943 when a wave of sabotage and labour strikes caused the Germans to install their own military government. Thankfully, many of the Jews were rescued before they could be taken.

Compare that with France, which also in theory remained in under the control of the Vichy regime. The French experienced harsh economic conditions due to the crippling reperations they were forced to pay, French men could be conscripted into German factories, and the Germans seized huge good stores leading to famine.

Now let's add in Greece. Greek partisans were especially nasty due to the huge amount of mountains and other partisan friendly territory. The Germans eventually began to massacre villages as reprisals for attacks on German soldiers. And even if you had nothing to do with the partisans you could be killed. There was also mass starvation due to Germany again taking food supplies and stripping the economy bare.

So as you can see German occupation varied depending on which country you happened to find yourself in.

Sources:

Third reich series: Richard Evans

The Second World War: John Keegan