1st. Make a list of all the tools you need to have to make what you are working on.
2nd. See if you and friend could share iron/cutting mat/ironing board/etc.?
3rd. Cut out at home the parts and label them/putting in baggies
So you can concentrate and not make mistakes; take extra fabric just incase is needed.
4th. Make sure your pattern is with the fabric/thread needed
5th. Snacks/drinks/bedding/etc. if not furnished
6th. Take some small projects along just in case you have time for something else.
7th. Know what is availabe at the retreat so you don't have to carry duplicates!!
8th. Go and enjoy the fellowship; I love going to retreats and have found I love them
more if I have already cut what is needed, so I can just sew, sew, sew!!!
9th. Don't forget the ripper!!! lol