Rubber finger tips from an office supply store to pull my needle through the fabric when I hand quilt. I keep it on my index finger right next to my thimble finger and it works great. I also love those tiny baby hairbands to put around a bobbin when I'm traveling with it.
I use plastic cafeteria trays to organize my cut fabric blocks for a project. I love sticky notes for everything from jotting a note about how many blocks or what size, color, etc. to put on that plastic tray to putting a note on my machine when I have a special setting in place or unusual needle to remind me to change them back afterward. Speaking of which I keep a little memo book by my sewing machine so when a specific setting works perfectly, I write it down there, so the next time I have to say zig zag two pieces of batting together I'll know the perfect settings.
I use permanent markers to mark specific lines on my ruler I'll need for a specific project and then just wash them off with rubbing alcohol afterward. (I'll bet the whiteboard type are even better)
Can't forget glue sticks. I've been using them for years. Elmer's glue is good too, any type that says its washable. I just give it time to dry and set before sewing through it.