Travel to Cuba from the US can’t be just for tourism. You have to have a specific reason such as journalistic activity, professional meetings, educational activities, religious activities, support for the Cuban people, atheletic and other competitions, workshops and public performances along with humanitarian projects
I would suggest traveling with a group where everything is taken care of. Taking a cruise is another good option. Here you can visit and not have to worry that your hotel is not on the approved list.
There are now many new commercial flights heading from various points in the US. Be patient as it may take a while for the system to be able handle the growing numbers. It can take a while to check in, clearing immigration or waiting in baggage claim when you arrive.
Make sure to keep your Cuban visa and return airplane ticket in your hotel safe. You don’t want to lose them as they may be very difficult to replace.
Only drink and brush your teeth with bottled water.
Credit cards or ATM cards are not usable, so make sure to bring plenty of cash to exchange into Cuban CUCs. A CUC is the tourist currency compared to the Cuban Peso, used by locals. You can do this at your hotel or at the airport when you arrive. If you have Euros from a past trip to Europe, you can bring them and exchange into CUCs without a fee. I opted to bring US dollars and not Euros, despite the fact that there is a 10% service charge when you exchange money. Your leftover CUCs can be exchanged at the airport on your departure.
Art collectors may want to bring more cash if you plan on buying art. Just be aware that more expensive paintings on canvas will require a permit for you to take them out of the country. The artist can provide this for you.
Be patient at the airport as the lines can be long. Keep checking the monitors for your flight departures as they they may not be announced.
Those needing internet connections should consider staying at one of the better hotels which have business centers and internet. The Nacional charges a fee for a certain number of days and hours over that period. I did have internet in my room which worked well. I found that I could not buy merchandise on Amazon.com and had trouble accessing other websites, but other than that it worked well. I found that my Verizon iPhone worked well and that my roaming was reasonable. You might check with your carrier before you go. I didn’t buy a package in hopes that I could use my app to call over WiFi, however the app didn’t work.
If you are traveling independently, make sure to check the insurance requirement by the government. Mine was covered in my package cost.
Taxis are plentiful and safe. Just make sure you ask for the fare before you leave.
Toilet paper in public toilets can be scarce. Particularly for women, I suggest bringing a roll and carrying it in your purse or tote bag as you tour the city. Toilet seats can also be scarce, so be prepared.
Bring all your toiletries and personal items with you, as you won’t find them in any Cuban stores.
I would pack mosquito repellent, particularly with the growing Zika virus scare.
Make sure you bring your two round prong “B” adapter to charge your phones and computers. I didn’t need it at the Nacional, but you may need it in others as some of the hotels have 220 volts and not 110.