The good thing about Cuba is that it's much safer than any country or place in similar conditions. I would rather walk in Havana during the night than in Miami.

Music, cigars, rums, the spirit of the people are not a problem. If you don't feel happy in Cuba, there's something wrong with you ;-)

Food is the biggest problem. Don't go to the government restaurants. If you have local friends, pay them to make you food. Or find a nice paladar, a private restaurant. You can eat good food in Cuba but not the way you can in other places.

Forget the big hotels and Varadero. There are quite a few small hotels in Havana that are restored old spanish palaces. They're a bargain to stay at, highly recommended.

Tourist money is important to the locals so many people will try to sell you something. That can be annoying sometimes but be friendly, they'll leave you alone if you're not interested. Pick an odd country to say where you're from if they'll ask.

Try to have local contacts, they'll make a big difference. Visit places like Casa dela Musica. Visit the museums. Bring some extra toiletries and other daily items to give to the locals if you make friends.