When it comes to tipping, I find that YPB's reccomendation differs greatly from the rest of the wedding coordination community, so I will give you both answers.
A) Martha Stewart says to tip all of your vendors 15-20% depending on how good of a job they did.
B) YPB says Martha's answer will get expensive in a hurray. Look, you are already spending a small fortune on this wedding as is. You are already paying your vendors a fair amount of money to show up, work hard, and do a great job. Unlike say a waitress, wedding vendors aren't working for their tips. Now if a vendor really goes above and beyond, or does a truly outstanding job, then a tip is great, and will be very appreciated regardless of the amount.
Two other notes: I do reccomend tipping your hair and make up artist, unless its the owner of the company, and also remember you are already "tipping" your catering crew with the service fee they included in your bill, so you do not need to worry about them.
Lastly, if you have vendors who have really done a great job, and you would like to tip them, put the amount in an envelope with their name on the envelope and we can take care of distributing them at the end of the evening.