Doug, I guess the most basic rule would be fairly obvious, and that is don't interupt a collector at a dealer's table by trying to trade or undersell that dealer for a chip.

I found that carrying a chip guide from an area that you have a particular interest will save time because the dealers will point you to the chips that they might have from that area so you don't have to look thru everything, it'll cause some to offer specials on what you collect because they don't collect your area but have some chips that they traded for anyway, and look for other collectors with area guides. Approach them away from a dealer table to talk trading. I think if you follow this basic advice, you won't make anyone angry, and should leave the convention needing an extra suitcase to put your dirty clothes in because you have more collectibles that you ever thought you'd obtain! I pack a fold up carry-on in my regular luggage just for this reason.

Have fun! <G>
Bob