So, stretch binding isn't really my thing. I've only managed two tops with bound necks that were remotely wearable, and one of them only works because the top is so slouchy!
This weekend however I made / altered a number of things, most of which involved stretch binding. I can't say I'm a pro now unfortunately - the last thing I made has ground to an unfinished halt after a few too many binding ****ups! But my technique has improved substantially.
Item 1 - recutting a neckline in a scuba dress.
I found this rtw dress and loved the pattern and fit. The neckline however I was underwhelmed by. I tend to avoid high neck things to avoid the dreaded 'shelf boob', and while this isn't too bad for that, it's a little sportier looking than I like on me. (I am not sporty - a few years ago I took a quiz on the BBC website where you put in your age and general athleticism and it suggested the perfect Olympic sport for you - I got lawn bowls.)
I cut in a lower scoop neck (luckily the scuba meant it wasn't going to misshape). I then thought I'd have a go with some fold-over elastic I'd ordered after everyone on the Internet talked about it all the time.
Now fold-over elastic is easy to use. Of course that does require you to use it properly. ... I did no research and plowed in. Do not try to insert it in one go. It doesn't work. At all. Look at this mess.
I did some googling (and cursing), and realised I should have sewed it on the back first, and used a zig zag. I cut off the previous effort (screw seam ripping!) And tried again. Much better! It is lucky I was using scuba though as a softer knit would probably not have been recoverable so easily!