I assume it's similar to what you would do with knitting. I knit on the looser size, so I use a smaller needle. Conversely, if you knit tightly, you would go with a larger size. If you're making clothing that is fitted, you need to do a swatch--switching the needle until you get the gauge that you need. If it's a scarf, afghan, etc., you want to be close--but it's not as important. Being consistent is what matters.
3a (Corkicelli), highlighted, fine, low porosity
modified CG, since April '07
CG since 3/11/08
HGs: Anything Sevi; Curly Kinks Satin Roots, Curlycue ReNew and Coil Jam; homemade FSG and okra gel; soap bars; UFD Curly Magic; Botanical Spirits Jellies, CJ Repair Me