Bust Fitting Revelation

I can actually bring myself down a size according to the following:

Find the crease in your skin where your arm meets your body. Measure above the end of one crease straight across the front of your chest to the end of the other crease. Round off the measurement to the nearest 1/2". Even though the front width measurement and its corresponding sizes are not written on the back of the pattern envelope, the sizing is easy to remember. (Not for me!) Misses size 14 equals 14" and the sizes go up or down with every 1/2". For example if your measurement is 13.5, buy a size 12. If you measure 14.5, select a size 16.
If you are unsure which of two sizes to use go with the smaller size. Remember, it is easier to fit the bust (to make it larger) than to fit the shoulder and neck area.

Page 9 in Fitting Finesse, Nancy Zieman

Quote found in a bulletin board post on patternreview.com. Isn't that amazing? No doubt this information is valuable.