If you are doing garter stitch--knit every row, you can count the ridges and multiply by two to get an easy row count. With garter, each ridge is really one row and each space between them is a row, but counting the ridges is easier.
For stockinette, I never count on the purl side because it's so much easier to count the v's on the knit side.
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog