For your outdoor booth the first item on your Must Have list is a tent. Most shows require that you have one. The tent MUST be white for the colours of your product to show true. It's heartbreaking to set up with all your beautiful work displayed under a green tarp that casts a bilious green tint over everything. Do not cheap out and buy the $35 tent at your local hardware store. The cheap tents are not tall enough, do not have walls and will blow away in the lightest of breezes. Walls are necessary in case of rain or wind and for leaving your display up at night.
When you've set your tent up your first concern is keeping it on the ground. Each corner of the tent must be staked to the ground. The stakes should be at least 12" in length and be hammered in at an angle (note: don't forget your hammer!). If the show is on concrete you will need cement blocks or sand bags that you can tie the feet of your tent to. Blocks are available at your local hardware store. You will need guy ropes from the top corners of the tent to the ground. Good guy ropes are available at Home Depot and other hardware stores. The top of the guy rope hooks onto the top of the tent frame or clips onto the canopy. The bottom clips onto a spike you've hammered into the ground (note: bring extra stakes in case you lose one). Many crafters find hanging a large weight from the top corner of the tent to be useful, it stops the top of the tent from blowing around. One option is to fill a small bucket or length of PVC pipe with cement and embed an eyebolt at the end. Personally I use a 5lb free weight on a long rope. Again, these hook onto the corners of the canopy. The weights from the top are very useful if the show is on concrete and you can't use your guy ropes.
Okay, now the basic structure is in place. In case of either rain or wind make sure your tent walls are somewhere easily reached and that you can put them up quickly. If you need a ladder to put these up then make sure your ladder is available and your display isn't in the way of using it.
Next is the display itself. Any photos/signs/posters that you are using should be laminated so that they can get wet. (I have mine laminated at Staples). If you have a product that can be ruined with water make sure you have several large plastic tarps or sheets that you can throw over in case of rain and remember to anchor them down! All your administrivia stuff (order forms, sales books, packaging etc) should be in waterproof containers such as plastic drawers or Rubbermaid bins. If it starts raining make sure you quickly put away any promotional materials such as business cards or postcards!
Wind is one of the worst problems you will encounter in your booth. Not only do you have to be concerned with windproofing your tent you need to windproof your display and your product. Hanging posters on the walls (hang them from the tent frame) is an excellent display idea, just make sure that if it blows that they will not hit your customer in the head. Take along a good supply of clothes pins, table clips (to keep the table cloth on) and double sided tape. In a good blow a lightweight jewelry bust can be airborne, use the double sided tape to anchor it to the table. Be careful of little objects such as earrings, they fly away, especially if they're on earring cards that aren't anchored down. Carry some rocks to weigh down items such as stacks of business cards. When you have your display all set up think about wind from all angles, what can blow away?
You should also think about heat. If it gets really hot you'll need airflow and won't want your walls up. If your walls are part of your display you need to find a way to open them at least partially in case of a heat wave.
Last on the list is dust. A show without rain is a show with dust. Take paper towels or rags and windex. All packaging should be in closed containers, who wants a dusty gift? All extra inventory should be in closed containers. Table cloths and any fabric must be washable.
With these precautions and thoughts you can survive most of the stuff that Mother Nature will throw at you. Craft show visitors are a dedicated and hardy lot and still shop in the rain. If they're willing to wear raincoats and shop in the rain, make sure you're ready to sell in the rain!
Oops, somebody didn't weigh their tent down. (not mine!)