One of the newer gadgets I use is the Add-An-Eighth ruler. This photo of the side view shows that it has an extra piece of plastic along one edge that is thicker than the ruler. This raised plastic is 1/8" wide. I use it to trim down the fabrics prior to sewing to make it easier to place the next fabric and keep my seam allowance 1/8" wide. This ruler is invaluable to me and if I broke it or lost it I would have to get another one immediately. This company also makes Add-A-Quarter rulers to use with larger blocks where you want to have 1/4" seams.
Also needed for cutting is a rotary cutter and mat. At one time I thought I should get the really tiny 18 mm cutter to use with my miniatures. Good idea but it won't touch the mat when used with the Add-An-Eighth ruler so it just sits in my drawer.
I purchase kids glue sticks and keep them in my refrigerator until I need them then put them back when I am not working or if they get a little sticky and then I exchange them for a cold one. You can extend the life of the glue sticks this way and don't have to toss the ones that get too sticky. I glue the first fabric down to the paper with the glue stick and glue after each seam I stitch. The just stitched fabric is folded out, seam creased then I use a tiny bit of glue to help it stay in place. This keeps the fabric from rolling back and getting tucks, plus makes piecing the really tiny miniatures so much easier. I sometimes even use a tiny bit of this glue to hold the fabric in place before it is stitched in the seam, especially if I just can't hold the pieces together and get it under the presser foot without slipping. I have used a number of brands and they all work fine. The funny thing about the glue sticks is that on the front they say "permanent" but in reading the directions on the package or on the side of the glue sticks they always say "washes out with water" so I don't worry about the glue being a problem.
After each seam is stitched it needs to be creased as if pressed. I don't use an iron as the paper can curl and then it is a bigger problem to stitch the next seam. I use different things to accomplish this creasing. I mostly use what is called a "wooden iron" which is a piece of wood with an angled end on it. I have also used a Hera marker, plastic pot scrubber, plastic credit card and even my thumb nail. You just want to remember to crease the fabric not just to pat it as it won't stay for you without a good crease.
My new Bernina 730 has some feet that would work for sewing miniatures but I still choose to use the #20 foot from my old machine as it will fit the 730. This is a machine embroidery foot has an opening that is only 5 mm. I found after getting the new machine that the corresponding foot for the new machine had way too big an opening for my tiny miniatures. Some blocks I have pieced in the past are only 1/2" to 1" square and the new wider foot just didn't hold everything down. I like the fact that this foot is open in the front and I can see exactly where I am stitching and can keep my line of stitching right on the line of my paper piecing pattern.
I select and use either #60 or #70 sharp needles and a fine two ply thread to machine stitch my paper pieced miniatures. I prefer using DMC cotton embroidery thread most of the time. If you think about how short the seams are on a 1" block you can imagine that you need to set the stitch length to take a much, much shorter stitch than you would when stitching large blocks as some seams may only be 1/4' long. With the shorter stitch you need less bulk with thread so that is why I choose 2 ply thread.
The last tool that I use no matter what I am sewing is my little curved bladed scissors. They are about 3 1/2" long and are made by Havel's and I like the fact that I can reach behind the needle and foot on something I have just stitched and clip the threads, plus these scissors come in handy for clipping threads on larger blocks too. When stitching small PP blocks I clip all loose threads as soon as I am done stitching them otherwise I can have a tangled mess on the back of the block real quickly. If you look back to the blog where I showed how to rip a fabric off of a miniature block when it is stitched incorrectly I am using these scissors too as they have very narrow, sharp points.
I can't think of anything more that I use for paper piecing miniatures right now. I pretty much follow the same technique for paper piecing that they show on the tutorial on the Add-A-Quarter website with a few exceptions. I don't press with an iron and I glue the just stitched fabric down after each new seam is stitched on the blocks. The explanation of joining the blocks is good on this tutorial too. I do trim my tiny block seams down to 1/8" after stitching them at 1/4", but make sure everything is OK before I cut them down. I press the seams between the blocks open after stitching them together too - it's all about reducing bulk in the miniature. Too bad there aren't some quick fixes to reduce the bulk on my body now!!!