If you want to work with an immigration representative, here are some tips you should follow. Tips for choosing an immigration representative. Make sure you get a written contract—read it carefully before you sign it. Make sure that all the promised services are listed and the fee is clearly set out. This card provides tips for interacting with police and understanding your rights. Some state laws may vary. Separate rules apply at checkpoints and when entering the U.S. (including at airports). For more information you can refer this link.