The Top Stitch (also called Tambor Crochet) is such a necessary skill for any crocheter that aspires to beautiful items (I know we all do), and its very easy. Once you get the hang of it you'll be drawing on just about everything you crochet.
It creates two different looks and you can pick and choose what you want your final project to look like. I've also seen it called Quilter's Stitch, Crochet Intarsia, Art Stitch, and Embroidery Stitch.
Bonus: I'll be showing this to you on a pocket (pattern included).
I once saw a woman, that just held her thread at the bottom of her work and starting 'painting' the most beautiful pictures - all using this stitch, the top stitch. I'm not that good, not even close, but I do love working with the stitch. Write your name, create fancy patterns, outline or create boarders, use it for embroidery. Get creative!
I tie my yarn to my start area. Pull the yarn through to the top (right side) and tie, having the working yarn (attached to the skein) at the bottom. If you are starting in the middle of your work, bring the end back through to the bottom (wrong side) and tie in the back.
Holding your yarn on the BOTTOM of the work draw up one loop.
To create the top stitch put your hook through the TOP of your work. Holding the yarn at the bottom, hook it.
Draw up a loop,
And much like a slip stitch, pull the loop through the one that was already on your hook.
Move one (or more) stitch over and repeat.
You create a line of loops as you go so you really can make some pretty patterns. And, as I showed above, the 'back' stitch is more of a dash. So you actually have two kinds of stitches to work your magic with.
Many moons ago (about 40 years, actually) I would make these pockets and simply sew them over my actual blue jean pockets (not removing the old pocket). This also makes a great pocket for any pair of pants, a western shirt, or actually any blouse or shirt. You can size it as you like and decorate it with your new stitch pattern. By the way, if you sew two together it makes a great protective sleeve for cell phones, tablets, a note pad, camera, or anything you want.
Check your gauge first so you can size it as you like. Your beginning chain will always be an equal number on two sides, +3 in the middle. Example: 7 + 3 + 7 or like the above one, 10 + 3 + 10.
Chain your number (in my case, 23).
Row 1: Single Crochet (sc) your first number (in my case 10). Skip 2 chains. Single Crochet (sc) your second number.
Rows 2 - 4: Chain (ch) 1 and turn. Single Crochet (sc) 1 into the first stitch, 2 into the next stitch and continue with your count (for me it would be 1 + 2 + 7). Skip the next 2 stitches and repeat backwards (for me it would 7 + 2 + 1). In other words you are going to always crochet 2 stitches into the second stitch. This makes up for the loss of the 2 stitches at the center.
After your first 4 rows you are going to start doing a straight Single Crochet (sc). Note that your 'center' stitches disappear. In the example with my work I'm single crocheting (sc) 20 stitches.
In the picture below I did an additional 20 rows after my first 4. Your gauge, and the height you desire, will determine your final row count.
Adding the Top Stitch, Tambor Crochet, you can make the pocket look exactly like you want it.