This is not meant as an exhaustive list, things change all the time so please don't take this as set in stone. However, the principles that apply to us probably apply to other shops and galleries so it may be useful to use this as a starting point for other sites.
Do some research!
Where possible visit the shop/gallery beforehand. Would you shop there? Can you see your work fitting in with what else is on offer? Do they already stock something similar to you? Which items are likely to be your biggest competition? Does their price range match your work?
As a general rule shops and galleries have lots to do in the background so just turning up with boxes of items with no prior warning will not get you the audience you would like. Try to chat to the owners first, find out how they like to be approached - or, if at all. And once you know this, follow the guidelines they give you. If they ask for 5 examples don't turn up with 20 - all this says is you can't follow instructions and therefore puts in question your ability to work with us.
Be aware of your prices - most galleries and shops will want to know your trade price. They then put a percentage mark up on to create the retail price. If you have really strong views about your sale prices say so, but be aware that if the gallery doesn't agree they are under no obligation to stock your work.
Don't be offended if they say no - sadly we say no to more than we say yes to. Mainly because we already stock similar work, it doesn't quite fit our audience or practical things like it would require specific display that we just don't have room for. It's not personal though. We are not saying we don't like you or your work is rubbish - we're just saying that at this time it doesn't fit in for a variety of reasons. Ask us for feedback on why not - is it something that can be overcome in the future? Also, please remember that sometimes our location restricts what will sell or won't sell. We have seen the most amazing pieces that would work in an urban gallery setting but not with us - each shop/gallery knows their own audience and can usually signpost you to somewhere where the customer audience would be perfect for you. We're not out to stop folk sellling - but need to ensure your work is sold in the most appropriate place for you.
Shops and galleries are in business - we need to know that the work we stock has a chance of selling because without sales none of us keep going so bear this in mind if you don't get the reaction you wanted. Listen to the feedback, it's not criticism it's feedback - big difference and it's there to help you. Sometimes we ask people to have a craft stall with us first because we're just not sure of public reaction. This is not a no - this is a genuine we're not sure so want to test your work out first before stocking it.
Also, and this is important try to do some research on what people think of the shop from a trader and customer point of view. If all the comments you see are 'what a lovely place to shop, so glad I found you' then chances are they will look after you too. If all the comments are 'please can you reply to my complaint' chances are something's not quite right. Use your instinct, you are about to leave work in the hands of strangers and trust that they sell it for you. We have come across some horror stories in our time which is why we always try to be as open and honest as possible.
Be clear on what you want out of the agreement - because it is an agreement between the shop and you. You as the crafter have the right to say sorry I don't want to leave this with you as equally the shop have the right to say I like the blue ones but not the yellow ones. Negotiation and communication are part of building a working relationship.
Visit the shop - everyone is busy, everyone has loads of demands on their time but just as you expect the shop to sell your work they expect some interaction in return too. Don't just turn up when you want your sales money, try to keep in touch or just pop in to say hello. We know from experience that the more folk pop in and check how things are going the more they get out of the arrangement. They can see customer reaction to their work, see what sells well and what's struggling. Also rotating and freshening your stock helps you and the shop. A strong relationship really helps in the future too, especially to those bribing me with cake :)
Be clear on what promotion you expect and ask the questions, again this is an agreement between two parties and you as the crafter have the right to query things. Without crafters we can't survive, without shops stocking work crafters would struggle - it's a two way process so remember that when you get all excited about being in your first shop then get home and think err I didn't ask whether they would actually put my stock out or just leave it in a cupboard?!