This is not meant as an exhaustive list of things to do or not do, and those of you that are more experienced will probably chuckle at some of the things you forgot on your first outing!
Firstly - don't panic! Easier said than done when you are surrounded by fabulous stalls that seemed to take no effort, but everyone started somewhere. Each crafter had their first stall somewhere - however slick and organised they may look today.
If you get chance go to an event, look around, talk to the stall holders. We all borrow ideas - especially regarding display from each other but far nicer to say 'wow that looks really good, think I may need to borrow that idea' because chances are you'll bump into each other later.
Look at stalls and think about it with your own stock in mind. Do you need to show off smaller items, or would yours look better hung up? Do you need people to be able to try or taste work on offer? Also, don't forget we never stop learning new things so don't expect to get it exactly right first time out. Expect to use each event to learn something new.
One of the things often overlooked is making sure people know what your work is for or does. Might sound daft but if you sell chalk boards make sure one is hung up with a piece of chalk and something written on it - you have now explained the function without having to tell everyone! Plus if you are shy it saves you explaining each time.
Change - again might sound obvious but if all your items are rounded up to the nearest 50p do you really need lots of small change? Plus, make life simple for yourself - round sales figures up or down to make your cash handling simpler.
Card readers - unless you already have one do not rush into a contract until you are sure it's worth it. Sadly you might lose a few sales, but the costs are quite high until you know you can justify it. Make sure you know where the nearest cash point is and offer to take a holding deposit while the customer goes to the cashpoint if necessary.
Tables, chairs etc - find out from the venue what is provided and what size. Also, it is worth asking if you have access to wall space or back boards to hang work on. Many venues don't but if they do then take full advantage to create your display. If you have a bad back or need to be seated for any length of time I would always advise you bring your own chair to be sure you're comfortable.
Power - if you need power it's best to ask the organisers in advance. Depending on the size of the venue this is often something they have little or no control over but if they know they can work with you. Arriving with 20 minutes to set up demanding a power socket is not going to make you their favourite person!
Temperatures - might sound obvious but make sure you are warm enough! If a venue is likely to be cold take a piece of cardboard or old offcut of carpet to stand on to stop the cold striking up at you. There is absolutely nothing worse than being cold while trying to be pleasant to customers.
Practice getting your stuff in the car - will your table, chair, 5 boxes, dog, child going to Nanny's actually all fit in? Also, try and pack so that tables come out of the boot first to help you set up more easily (don't forget to take the child to Nanny's either).
Leaflets, business cards, flyers - it would be wise to print off some simple A5 leaflets that tell people who you are and where else they can buy from you with the details you want them to find such as your Folksy shop or facebook to contact you.
Layout - you will probably be stood behind your stall all day but have you looked at it through a customer's eyes? Stand at the front, make sure you can see everything, is it priced up, can you reach things to look at them, does it look interesting? Or, if you have a willing assistant set it up at home first and ask them to look objectively. Mixing height is a good way of making a stall look interesting. Concentrate on using your most attractive items to draw folk in, or maybe you have an unusual gimmick that draws conversation? Anything that gets folk to stop, chat and engage is helpful. Don't forget, you don't have to stand behind a table all day - you can often change layouts to make it a little different.
Talk to customers - craft fairs are a social outing for both you and the customer, they are usually really interested in how or why you make things so take the opportunity to share what you do. Sitting down all day with your nose in a book will not gain you the highest sales of the day! If you are able to actually demonstrate what you make then do it - people love to watch crafters at work, plus it proves that you really did make all the gorgeous things you have on display.
Share - make sure you take your details to share amongst the other stall holders and get their details too. It's surprising how many times the same faces pop up so it's far nicer to be able to chat to them between events and possibly share ideas or suggestions.
Be realistic about what you expect from events - unless you are very lucky and have a loyal audience you are unlikely to make your fortune on your first outing. Or, is it more realistic to use events to generate new business leads? If you have food products be sensible about quantities and use by dates. It is better to sell out of a smaller volume than have to take home 50 unsold cakes (however happy your 6 year old is with this idea!).
If there was something that was really bad make sure you tell the organisers - sometimes they are unaware of your issues and without being told they can't put it right for next time.
Above all - HAVE FUN!! You chose to do the event, you spent the time making your goods and you paid to be there. There will always be good and bad events, grumpy and happy stall holder, organised and disorganised event organisers. Trust your instinct, if you think it's not right for you then don't book. There are many different events for different audiences and in time you will find where you best fit.
Hope this helps, and if you have other bits to add in please do so. Hippo x