Tess

The wash test matters double here, viscose can shrink noticeably and unevenly on the first wash.

Two practical things before you cut into two metres you love.

Wash a test square first. Cut twenty centimetres square, measure it, wash and dry it the way you intend to for the finished garment, measure again. Viscose can shrink a lot and it does not always come back. Doing this on a square costs nothing; discovering it on a finished dress costs the dress.

That test also tells you whether it creases badly, whether it survives the iron temperature you plan to use, and whether the colour moves. All useful before you commit.

Make the bodice as a toile in something similar. Not calico, calico is crisp and will tell you nothing about how a drapey fabric behaves. Use a cheap fabric with roughly the same drape; an old sheet is usually too crisp, a charity-shop dress in something fluid is usually right.

And since you buy fabric first, the habit worth building is to note what you think each piece is for when you buy it - crisp shirt, fluid dress, structured jacket. Two words on a tag. It stops the pile becoming a collection of things you love and cannot place, and it is much easier to judge a fabric's behaviour in the shop with it in your hands than at home from a photograph.