When paper-piecing, this is usually what I like to have on hand.
ruler no. 1 : (4″ x 8″) My no. 1 for sure. The small size fits in my hand and covers most bases. Plus, I really like the 1/8″ grid. It’s handy, except when I’m working on something longer than 8 inches. Then, I’ll move to no. 2.
ruler no. 2 : (4″ x 13″) She’s pretty good too, and along with no. 1, I’ve got most situations under control. The markings are OK, but I still prefer no. 1′s abundance.
rotary cutter : You’ve gotta be careful with this one, no question. I had a little accident a couple years ago that resulted in a trip to the ER and some stitches. In architecture school, cut fingers were a right of passage for many, and somehow I managed to escape without partaking. There goes that.
cutting mat(s) : I have several, and each is good for different things. In general, whatever size work space you have, get a good, self-healing mat to fill it.
rotating mat : To be honest, I was a little doubtful when I received this one as a gift, but to my surprise, I use it all the time.
pins : I pin everything and have a growing collection of all types. Currently, I’m using some really thin ones that might be for silk (not sure). They glide right through the fabric. My magnetic pin cushion may not be a looker, but she keeps the pins together nicely.
multiple waste baskets : I try to limit the amount of waste that I produce, so I have one for paper (to be recycled), one for fabric scraps (to be repurposed), and one for anything else.
other stuff : iron (very necessary, keep it close), seam ripper (for me, a little “reverse sewing” is needed from time to time), lint brush (always), extra needles (I’m getting better about my breaking needle habit, but still), some scissors just for paper, and some scissors for thread.
May you go forth equipped.