comfortable shoes, comfortable clothes; plan a budget & only take what you can afford to spend- it's way too easy to spend way too much really fast.
browse and wait- then go back to the vendors booths you really want to buy from. I always put a certain amount of $$ on a pre-paid Visa, then take a specific amount of cash & leave the rest at home...
if taking classes/workshops check over the descriptions/supply list/necessities ahead of time- go prepared & on time.
take the time to enjoy& watch all the free demo's...try out lots of things that may interest you- try things out- ask questions- if an area is crowded, simply continue on- then wander back that way later- it will still be there & may be easier to enjoy, experience when you go back. pick up business cards, newsletters, flyers to look through later at your leisure.
enjoy yourselves- smile lots, take breaks when you need one.