You're looking to add something called a "gusset".
You can add a gusset where the underarm meets the shirt, and it helps with these problems.
https://www.threadwerk.com/post/how-to-sew-underarm-sleeve-gusset
A place to share ideas, knowledge and creations with textiles. The focus is on reducing waste, whether that be sewing from the scraps left from other projects, using the end of rolls and remnants, or repairing and remaking finished pieces.
You're looking to add something called a "gusset".
You can add a gusset where the underarm meets the shirt, and it helps with these problems.
https://www.threadwerk.com/post/how-to-sew-underarm-sleeve-gusset
Yes this exactly what I'm looking for. Thank you! With this word in we'll be able to look for ressource on this. I'll read your article as well of course :)
It sounds like both are examples of too much material being cut away. Either too little space in the shoulders, or just not enough sleeve material.
You could make either example into a tank top. Adding material in is pretty much always going to be really hard and result in a fundamentally different piece of clothing than you started with, rather than a typical alteration where you're removing material.
If they're a way you can remove material to get something you'd be happy with that's definitely the easiest route- like making them into tank tops. Or cutting and hemming the sleves so they're intentionally like half or 3/4 sleeves
I really need to learn how to alter clothes. It seems more and more like a necessary skills given the state of the industry.
I got started by learning basic hand sewing and mending stuff I thrifted- I feel like that's one of the easiest ways to dip your toes in and start getting comfortable with it and building skill :)
When you're hand sewing you place each stitch one at a time, so it's really easy to feel in control at every moment
Regardless, good luck my friend :) if you decide you wanna pick up a new skill I'm rooting for you!