Something I always feel especially glad to have is those tweezers with the bent ends on them. I use them to thread the machine (especially pulling through from behind the needle), pull up bobbin thread, turn edges under close to the needle, grab stuff that fell behind the desk…. I can’t think of all their uses right now.

I have a favorite seam ripper. The blade is one end and the other is a curved point that is ideal for poking out corners, flattening seams, etc. I use it more than I care to admit 😀 but when you need to try again there is nothing else that works as well.

Rotary cutter and a cutting mat. Made cutting fabric so much easier, especially since my hands quickly get tired from using scissors.

I have another one: A mini iron to press seams open!

(...she wrote, sitting in front of her sewing machine, having sewed a seam that really needs to be pressed open before proceeding, and having spent the last five minutes trying to press said seam open with the handle of her shears, because the laziness is strong with this one, and who can be bothered to stand up to set up the ironing board?)

The Dritz seam gauge with the different seam allowance widths from 1/8" and above. Not the slide rule-looking one. This is a many-sided shape. It makes marking things so easy. It's metal, so you can iron over it.