I have some experience with visa applications. My family lives abroad but comes to visit me several times per year. I know they always have to fill out visa forms and this is what they tell me:
- give yourself good time to complete the application
- always book an appointment at the U.S. embassy well in advance
- you must get the supportive documents together such as bank statements, insurance, tickets, etc etc. This is very important
- always bring all the supportive documents with you when you enter the U.S. You may have to show all of this to the immigration person
- don't overstay your visa. This is will only give you problems in the future

I hope this helps. Good luck with your application!