a round needle size US13
3 balls of Knitpicks cotton yarn (which you can find here: KnitPicks)
and for the straps I used US9 needles
I doubled up the yarn (using two different colors at once) and cast on around 100 stitches on my round needles. I knit 4 stitches and then purled 4 stitches back and fourth for the bottom of the tank. Then I just knit until it was the length I wanted, occasionally decreasing stitches. I ended up with 80 stitches at the top of the tank top. I then just cast off.
For the straps, I used my size 9 needles and cast on 5 stitches. I knit until the straps were the length I wanted (around 50 rows) and then sewed them onto the shirt.
If you have any questions about how I knit this tank top, please just leave a comment below!