Tip 1: Always consult with a lawyer before you file. You don't necessarily have to hire a lawyer to follow through your case, but it's always good to at least consult with them to understand the possible complexity of your situation
Tip 2: Never trust the online status check on the USCIS web site or the 1-800 National Customer Service Center for status info, they're WRONG and NEVER GET UPDATED!!!! If you believe you have been waited longer than you should, you should not hesitate to check your status. Don't call, WRITE! Write directly to the National Benefit Center and the real immigration personnle WILL RESPOND!! Even though it takes a little longer to get response through writing, but you'll get REAL status update. The customer representatives at the National Customer Service Center are all contractors and they don't really work for USCIS, they don't know nothing about your case besides giving you useless info.
Tip 3: Always provide more than the minimum requirements. For example, when they ask for minimum 1 year of tax return to show Affidavit of support, make sure you provide 3 years and so forth. Again, the best thing is to consult with the lawyer and they can provide some good advise. The more complete info and evidence you provide, the less chance they'll send RFE asking for clarification or additional evidence, and the quicker the process will be and also less chance of losing any RFE in the mail (like me
And lastly, wish me luck in getting my EAD before my TN expires in December 2007
