Make sure you get scales, then there wont be any disputes between customers getting different weights to each other. If you want, you can also get like 10 packs of small zig zags for like £1, give some of them out as well with your deals, it makes the customer happy and that's what ya want: returning customer. Also, if you can, blaze when ur dealing, it makes the buyer much happier if he can see that ur stoned off the stuff hes buying from you because he can tell it must be good.