Citizens of most countries must apply for a tourist visa to enter the United States for tourism purposes. During an interview, you must prove that you'll be visiting the United States only temporarily and that you have compelling reasons to go back to your home country. You must also prove you have enough money to fund your vacation. Nothing can guarantee that you will pass the interview and get a visa. However, thorough preparation may improve your chances.
Consider making trips to other foreign countries other than the United States.
Don't be in a hurry to make a trip to the U.S. especially if it is for pleasure only. Travel to other foreign countries where it is easier to get a visa and do not overstay the visa. Doing so may help establish a "credible" travel history on your passport that may help you pass a tourist visa interview later. Besides, there are many equally interesting places to visit than America.
Obtain proof of ownership of assets in your home country.
Secure documents that prove you own a car, a house, company shares, significant bank savings, investments and so on. The more assets you have in your home country, the stronger your ties will appear to be.
Consider getting proof of employment or enrollment if possible.
For example, get a letter from your employer or principal stating he or she is aware of your trip, that it is legitimate and that you are fully expected to return. Gather proof that your job is stable, well-paying and worth holding on to. If you're a student, prove that you have an impressive school record and have a big future ahead of you in your own country.
Obtain proof of strong ties to family.
Get this as supporting evidence only. Don't expect the consul officer to believe you will return to your home country just because you have a sick mother or child to take care of.
Consider making a compelling appointment or commitment that you intend to fulfill after your visit to the US.
If you really plan to return from the US after a specific period, you won't hesitate about making a commitment in your home country if it's in your plans. You can enroll in a law school, for example, if that's what you want to do. Mention this to the consul officer and show a letter of admission as proof.
Save enough money to fund your trip and then some.
Show proof of income not just to demonstrate that you can fund your trip, but more importantly, to show that you are stable where you're at. Save records of your bank statements, going back at least 3 months (or depending on what the US embassy requires).
Familiarize yourself with your own visitor visa or tourist visa application.
Review your forms and documentation carefully. It's easy to neglect this if you were sponsored by another person. Make sure you know all the details by heart so you can answer the consul quickly and clearly at the visitor / tourist visa interview.
Prepare your documents and evidences.
Organize your paperwork. Make sure all the information is correct and that nothing is misspelled or erroneous. You should be able to quickly and easily retrieve anything the consul officer asks for.
Arrive on time with the interview appointment letter.
Dress well for the interview. Bring all required documents as listed in the interview letter. Include your evidences. Be ready to called any moment. You will be fingerprinted and your photo will be taken.
Stay focused during the interview.
Bear in mind the purpose of the interview. You need to convince the consul that you are not entering the U.S. with the intent to overstay indefinitely or get a green card. Emphasize your ties to your country. Make clear the purpose of your trip, how long it will take and why. Be ready to answer questions about your job or schooling. Make it evident that you are happy in your country and that a visit to the U.S. is just that - a visit.
Be mindful of your attitude - and the consul's.
Don't try to overdo yourself during questioning. Don't wisecrack or tell jokes unless you're willing to risk it. Be sensitive to the consul officer's personality. Do smile and be polite, but keep focused on what's at hand. Remember, it is the consul who will decide if you pass the tourist visa interview or not. Do not lose your cool.
Pass the tourist visa interview.
If you pass the interview and are granted a visa, the consul officer will tell you so. You will get back all your original paperwork except for your passport. They will take it and stamp it with a visa. It will be delivered to you or you may be asked to pick it up in person.
If you are denied a visa, you will be told why. You may also receive a letter of denial. The consul will give back all of your documents.