Of course as the flasker, you run a substantial risk of making many replates of a 'cattleya' and the customer backing out at the last minute, leaving you with absolutely nothing but wasted time and space... Oh, do I sound bitter?:arrr: But really, any lab that resells your crosses without permission (ie. steals...) won't stay around long.
Anyway... Trust is an essential part of the relationship between breeder and flasker. Don't send valuable pods to any old schmuck with a website. Send some less critical seed, see how it goes. Check reputations, references, whatever it takes to get an idea of trustworthiness. Equally, as a flasker I have to trust you. Are you actually going to pay for the flasks you order, or get cold feet at the last minute? Are your crosses worthwhile, or am I just adding to the crap-fest on e-bay? Personally I won't bother with stupid breeding (risky breeding, sure - stupid, no).
Expect to pay some modest fee up-front just for the initial flasking of seed. Your seed may or may not be viable, and it may or may not be contaminated beyond repair. I don't think it is reasonable to expect a busy flasker to figure that out for free. I think you should expect to pay a substantial portion of the final price for replating up front if you are sending anonymous seed. I would insist on a deposit, or I won't replate it (when and if I get my lab back together, that is).
Do assign your crosses a unique identifier of some sort. The initials of your business, yourself, your dog, whatever, plus a string of digits is a good start. So I make my crosses LFF1201, for example. Keep a record of what cross goes with what number, when you made the cross, how long it took to mature the capsule, and whatever you can think of. This number will follow your flasks around, so don't lose it (I'm not writing out your cross on every flask!).
Oh, and don't just assume that your favorite lab will have time to flask your seed. You need to communicate before sending seed! Maybe they are swamped and just won't have time to do it. Maybe you are making a cross outside of their area of comfort (I might not want to flask a cyp cross just yet, for example). If you want start breeding seriously, make sure you have two or three labs that you can trust (or better yet, your own equipment).
Just some thoughts...