aashley333

I mean an existing tool that you just discovered!
I really enjoy using the plastic handled tool with a wooden roller on the end. I use it when joining rows and columns. It helps tremendously when pressing the seams.

quiltingcandy

For me it's the clapper. It's been very rare for me to open my seams but lately my blocks have required it - and I found a clapper with a wool covered piece that the block fits over perfectly and my full sized iron slides easily. Sorry I am not describing it very well, this tool works so well because of the weight of the item and the length.

Onebyone

A tool I had no idea I would use as much as I do is the Thread Genie:

https://www.missouriquiltco.com/prod...39280773201955.

The tip is so fine there are no burn marks at all. Great for tiny thread ends that stick out and I use it to instantly take thread ends off quilt top without using scissors or snips. No danger of cutting the fabric.

Onebyone

Quiltingcandy I have this clapper with wool bar. It's great for pressing opening seams. I think it is what you are describing:

https://www.fatquartershop.com/12-in...-gypsy-quilter

mkc

I have a floor-standing 3-axis positionable OTT light that has a magnifier and binder clip arm as well. It's at my cutting cabinet. I rarely need the light or magnifier, but I've been working on a more involved pattern and the binder clip arm has been priceless for hanging the instructions at eye level while I cut and arrange, and I can see it from my sewing machine to double-check my piecing orientation.

Tartan

Rotating cutting board. I have a cutting mat on an island that I can walk around but the rotating mat makes cutting small pieces much easier.