I remembered another one - prices on EVERYTHING... you may be independently wealthy - but I am not, and I cannot buy it just because I want it with no regard to price...
If I come in to browse I don't want to have to keep asking the price of something...
And don't change the price of 'whatever'... (unless it's on sale) - don't let the customer get to the cutting table and say "oh, this is supposed to be marked suchandso"... (believe me it has happened, guess what?, I didn't buy the fabric)
And if I ask for something don't say, "We can order it" - you know what, so can I.... and probably much cheaper than the LQS will sell it