Here's what I teach new knitters to do:
Place stitch markers across the row, every 10 stitches.
When you get to the end of the row...count between each stitch marker to make sure there are still 10. If not, you'll quickly know which section lost a stitch.
Here is the illustration I recently gave to a new guy knitter:
"Think of yourself as a school bus driver. You are taking 40 kindergarten students on a field trip. The field trip involves stopping at 4 locations for 1 hr each. When the bus is ready to depart for the next location, doesn't any wise bus driver do a head count? To make sure he has all 40 kids?"
Well, knitting is like that, too! Perform your head count at the end of each row before turning the work and heading off to the next location (the other side of the knitting!).
Conversely, when you are working a piece of lace work, where there are K2Tog's and yarnovers...doing the head count assures you that you haven't lost a kid, or picked up an extra kid!
I still use stitch markers on all of my projects, for various reason...and many times to keep track of stitches on long expanses of rows.
A ounce of prevention is worth a pound of cure.
It's always easier to pick up a dropped stitch right away, before turning the work! If you wait a dozen rows to finally come to the realization that you are a stitch short...it's much more difficult to find the "lost kid"!
I am a confirmed believer in fixing mistakes, and finding my lost kids!