I got a request what to do when your normally wearing a size lets say 36, but you have a cup D or DD, so most things never fit. Actually I know that problem, thats why I wear so few blouses, because most produce a gap between my breasts because german sizes think every woman has cup B but mine is C/D, so most T-shirts still fit fine with me thanks to the elastic, but everything more tailored is a little complicated. Well I did the pattern in 1:5 so it would be faster and easier to do and did it for the possibility of darts in the front or a seam if the front. Even when you changed your pattern up you should do a muslin as for all tailored items so you can check the fit and maybe change it a little for the better. Dont skip that part because you are in the hurry. Maybe you are lucky, but most likely it will cost you more time in the end because of undoing the seams quite a few times…. maybe you even lose money because you cant save it and your good fabric is gone. (Any cheap un-elastic fabric will do. I personally use the old tablecloth of my grandma, they have stains that dont wash out anymore and she does not do big parties anymore so she gave them to me, they are a nice soft cotton/linen and perfect for testing the fit of patterns)
I did this ones starting with the small size and adding space to the bust area, if you have a pattern in a size fitting your bust, but is way to big at all other parts please let me know and I will do another tutorial for that. If you have some other problem with your body-form and would like a tutorial like this, please tell me, even though I am in a tough schedule at the moment I do my best, so you dont have to wait for long. If there are any questions feel free to ask in the comments!
so first of you have to measure from the shoulder to the waist over the highest point of the breast ( best wear a normal bra for that) and then you need to measure from the side ( where the side-seam would be) to the middle (if you are not sure about the middle, measure side-seam to side-seam and divide by 2) thats the 2 measurement you gonna need, since you already picked the pattern where all your other measurements beside the bust should fit.
mark those 2 lines in the front-part of the pattern, straight lines starting from the dart-ends (the back part will stay the same since your additional volume is only in the front), measure those lines, you need the difference to your measurements
cut the part at the line through the bust-dart and add the difference between your measurement and the actual line in the pattern buy glueing it onto another paper (here orange, I made this colorful so its easier to see, my imagined person needed 2 cm more)
take the points where the original dart ended and draw a new point in the middle of them to draw your new dart
next cut the other line and split the part at the breast area about the difference between your measurement and the actual pattern line, but dont split evenly like before but keep the shoulders at the original measurement (unless you need extra cm at the shoulder) then redraw the waist-dart with the same method as the bust-dart
and that part if finished and can be sewn with all the additional original parts in a testversion (muslin)
if you pattern has princess seams draw a line through the highest bust point as you see I made a little mistake and did it a little to high, thats why there is a bump under my orange line. add the difference between your measurement and the actual line again
then add half of the difference between your other measurement and the the actual one to each part and draw new lines (they should go back to the original lines at arm-hole and waist)… this might look a little funny and even more so after fitting and correcting a little (looks always funny when I do it) but it is important it fits not that it looks normal. control if your new lines are the same length, because you need to sew them together later. Best do a marking at the bust-point when sewing pattern like this.
I made a little mistake with this, you need to keep your side-seam as it was, so you can keep all other pattern-pieces the way they are.
Of course this alterations also work with dresses and longer blouses, just be sure your back to the original lines at the waist. then leave the rest of the pattern as it was.
I hope this helps and let me know about any questions left!
keep sewing and smiling