A great excuse would be to say you wont be playing long. When that thought is in their head, they may feel its a waste of time to watch you because you may not stay long enough to get a read. Say something like "Im probably only going to stay a couple minutes, im waiting for a phone call from my boss."
My recomendation for comps is to get a fake ID or sign up using something other than a drivers license with a differant name. I have multiple accounts in a few casinos because I have a hyphenated last name so when I sign up, I say just put it under #### and another day say the other name. You dont really need a license to sign up in the pit. Where I used to work, we used library cards, student IDs, and being downtown, prison IDs. A simple fake ID would be to get an authorized user on your visa card and have a card made in a fake name. I got one with my dogs name a couple years ago and it just said "Loki" with no last name, haha. I did it just for the hell of it before i moved to vegas just so I could show people my dog had a credit card, but I know you can put any name for a visa authorized user. When asked for your ID, say your wife has it for some reason and ask if they can use that. I never refused when I was the boss and I havent seen anyone have a problem.
Also remember, the larger the buy in, the more power you have over the floorman. A guy came in to my current casino about two months ago and after buying in $5000 demanded a players card with the name "Clark W Griswald". He instantly became my hero, even before he tossed me $400 for his $2500 win. That was all the information they got from him, but they gave in and printed the card. He was doing impersonations and quotes from Vegas Vacation while he played. Good times.
Find out how much you must buy in to get rated at the property you are playing. Many, like where I am at now, require >$200 to be logged in the system, everyone else using their card gets a temp rating which gets you food the day you play, if you ask, and is never recorded in the system. Comps are based on a multiplier using average bet and time played. If your not going to be playing for long and your average bet is going to be less than $20 per hand, its most likely not worth it to have them rate your play. Unless you win a substantial amount or are playing suspiciously where they end up entering a warning on your account to let the floormen know to watch you closely on your next visit, your play notes will most likely end up in the trash can. If your playing downtown, you get more appreciation for low limit play and if your going to use a players card anywhere, that would be your best choice.
If you give a players card, its easier to tell if you have heat. If the pit has your card and you are betting with the value of the deck and being watched, keep an eye on the floorman and if he goes from watching you to typing in the computer, he is likely reading notes about previous play. Along with logging win/loss, the pit can write detailed notes about your play and even instruct the next floormen to back you off if they didnt get a chance.
If you are a first time player, it isnt too suspicious to play without a card, but once you are seen a few times, it may raise an eyebrow. If you are playing high limits, it is less likely that anyone would be suspicious for you refusing free stuff because the pit will assume you have plenty of money, and don't need their free meals or rooms and may even help your cover. Appearing to not care about money is a great cover and makes the pit boss think you will eventually lose so it is ok for you to win for now. Nothing beats laughter and a genuine smile as the dealer flips over their blackjack.
As an alternative, become friends with a pit boss like Zengrifter and I, and when that pit boss leaves the company, you suddenly have over $2000 in comp credit ready for you on your next visit.
