I have a long torso. There, I’ve said it. Although my fiance thinks that the way to make it look shorter is to wear shorter shirts (so it looks like my torso ends at the bottom of the shirt, not several inches below that), and higher-waisted pants, well, higher-waisted pants haven’t existed in about a decade, meaning short shirts show my midriff, or at least very barely cover it. Nobody needs to see my midriff. I am SO happy that the trend the last couple of years is towards longer, slinkier shirts and tanks. These make me feel long, but lithe, even if the objective view is that they make me look like I have a snake-body. Whatever.
This is how to take a shirt that is too short for you and turn it into a no-sew tanktop that’s prefect for layering.
If the shirt is too short, the neck is probably also too tight, yes? Cut it as open as you need/want. You could even go for a V-neck if you like.
Cut off the sleeves of the tiny shirt. Now take a sleeve and cut it into one strip of ribbon (1/2 to 1inch wide) by cutting in a spiral. If the sleeves are small, you might need to do this for both sleeves.
Cut open the seam at the shoulder of the shirt, so the sleeve is now in two pieces. Cut a small slit 1/2 to 1inch down from the top of the sleeve, on each of the two pieces on both shoulders. This is where you will insert the ribbon to create the extended straps. First knot the ribbon on the back shoulder-pieces. Put the shirt on over a tanktop, and play around with the length of the shoulder straps. You could even cross the straps at the back. When you figure out what you like, just knot the straps off at the front. Another option would be to taper the shirt’s shoulders, so instead of creating slits and knots, you just tie the ribbon and the shirt together.
(I think on my shirt, I slit&knotted the back straps, and taper-tied the fronts)
Easy peasy. Torso under cover.