Cut or Tap??
When you start your game, you have the option to cut or tap. Each game I go in with a different approach as each game is also different.
You are allowed to cut at any point in the deck, whether it be a few cards in or more than half the deck. I prefer to switch it up and never cut in the same manner. You are technically not allowed to make more than one cut as per the rules.
There is also the option to shuffle your opponent's deck, but remember it's not your deck and you must be careful when handling another player's property. It must be a quick shuffle. Your opponent has the option to cut after you are done shuffling.
You are also allowed to ask a judge to shuffle if you feel your opponent did not shuffle correctly. No one is allowed to cut or shuffle after a judge has shuffled.
In normal fun games, I usually tap and decide not to cut my opponent's deck. There is also the case that opponent's like to middle stack their deck and cutting could give them an advantage, some players are known for this and you have to be careful.
As long as you treat your opponent and their property with respect, cut, tap or shuffle are your options to choose.
The Frugal Dutchman