Write you name on everything you can.
I have my last name ( it is unique) and telephone number on my machines, foot pedal, power cords, scissors, rotary cutter cutting mat, tool box, machine case etc, in indelible ink. I do not just tie a ribbon to the handle of my scissors.
Remember to write you name on your patters (each page) any notebooks you may bring too.
I had never had anything go missing before I started to do this, but I had been in workshops where other people had things go missing.
A friend forgot her machine's power cord. Luckily the shop that was doing the retreat was able to loan her one for the weekend.
If you have time for multiple projects bring the fabrics, pattern, template, thread etc for each in a separate tote.
I am a tea snob and bring my own tea. I do bring enough to share with others if they are interested.
I also being fresh fruit. I used to bring carrot sticks, but the crunching, (I guess I am a noisy eater) can annoy others. I also follow a primarily Gluten Free diet. I make sure I bring snacks that I can eat and again enough to share.
Have fun!