When working flat, there isn’t anything easier than garter stitch. No decisions to make or rows to count; just knit every stitch and count the easily-countable ridges.
But in the round, you alternate knit and purl rounds.
Which one to start with? If you are starting from the cast on edge, your first round will be visible at the cast on edge. I usually start with a knit round.
How to tell what round you just did? Garter stitch can be challenging to decipher. To see what you just did, look at the round closest to the needle. If there are bumps right next to the needle, the next round is a knit round. If the bumps are one stitch away from the needles, it’s time to purl.
The New Bittersweet Cowl (seen above) starts and ends with a few rounds of garter stitch.