Oh yes... I always do the inside bit as a 4x4 square...
So if it says 5 st x 7 rows = 1 inch, I would knit 20 st x 28 rows (not including the 3 stitch/row garter border) and then measure.
A one inch square always seems too small for me to be sure.
Also, if I'm nervous about wasting the yarn (say, I only bought enough for the pattern) I will knit my gauge swatch, measure, and then unravel it and re-roll it onto my ball without cutting the thread.