Checked luggage versus Carry on luggage?

The only current restriction is for carry on liquids. There is no restriction on the amount of liquids in checked bags. Put all your shampoo, conditoner, bath gel, hair spray, hand soap, body lotion, water bottles, etc in your checked bags and don't worry about it.

Can you carry more than 3oz of liquids/gels/etc. in your checked luggage? According to the U.S. TSA: 'Most items can be placed in your checked-baggage without a problem' and 'If you need larger amounts of liquids, gels and aerosols such as toothpaste or shampoo, please place them in your luggage and check them with your airline'.

So assuming you're traveling within the US, the answer is yes. There could be different rules for travel outside the US.

I’m a security officer for TSA and can tell you that the exact amount is 3.4 ounces (100ml) for carry-on bags (one quart size baggie per person). Anything over that like liquor that you buy from duty-free is allowed and has to go on your checked baggage.

TSA does not prohibit the amount of liquids, gels etc. you can travel with but restricts the amount of liquids, gels, etc. you can have on your person. In other words the amount you have immediately accessible to you.

Though I am not worried about your luggage being lost, I would be more concerned that if any flight segment is delayed, you can possibly miss your other connections. In my opinion, the intinerary with the fewest connections is best. If your flight has to have 4 stops, then give yourself a bit of cushion for each connecting flight so that your bags have time to make it to the next flight.

Unless you plan to wash your hair at 30000 feet why are you even bothering?

You can put whatever you like in checked luggage subject to restrictions for dangerous items. Though if you are concerned about Carbon dioxide emissions then think about how much it takes to carry your stuff to where you are going. Why not buy it at your destination?

I travel all the time...you can take the whole bottle with you as long as it is checked in.There is no limit on how much liquid you can have with you in your checked in luggage.

Yes, you can put larger gels and liquids in your checked bag