My quilts start out planned. If it's for my bed sometimes the plan can change.

I usually go by the pattern but I do like to make quilts in my bed size if its for me

Thats usually what happens with my quilts too.

I usually have a bed size in mind when making a quilt. If it doesn't fit the size I'm aiming for, I add more to the top before quilting. I like them to be large enough to go over the bodies sharing the bed..and still have some hanging over the sides.

I'm pretty sure it's important to a quilter's sanity if she/he is flexible.

My quilts/sizes are planned ... sort of! However ... things don't always fall in with my original vision. When I got the idea, "I'll make a Grandmother's Fan quilt and use up these many yards of lace I've had for 20+ years", I ordered 8 'coordinated' colors of fabric of various lengths. A couple of weeks ago I washed, starched heavily and pressed it all. Not only did the combination of colors look hideous, but I only had enough lace for 18-1/2 fans instead of the 20 I wanted. I didn't find a pleasing layout for an 18-fan quilt, so am using 16 and only 3 of the fabrics ... it will be a lap quilt. I bought 2 more fabrics this past week for wide & narrow borders and I'm happy to say that they are perfection, so I did a fairly exuberant happy dance after UPS delivered them yesterday a.m.

When I stop sewing on it? Not being a smart ___ here but that is what I do.

It's not saying one day I won't have an actual design and size.

I sew pieces together and when I stop that is the size.

All of mine are planned and made for a specific purpose. I don't have time to make random quilts.

I do a lot of bed quilts and they are planned. The throws I do not plan as much, larger if they are for a guy or smaller for a child.

I have made more lap quilts and they end up as they end up.
Practicality, pattern on fabric, and size of squares or background usually determine this.

I plan them to be a certain size. Occasionally it will be
for a double bed, but must are queen or king, as that is the
size bed most of our kids have. It doesn't necessarily mean that I find a pattern in that size. I just finished a king
size that started from a 9 block wall hanging. Some are very difficult especially if they are large blocks..as some
times another block wide or long, makes too much quilt.