You've got a ball of worsted-weight yarn and a hook, you've watched someone do it, and now the loop on your hook keeps sliding loose before you can pull the next one through. Nearly every crochet project begins the same way: a slip knot on the hook and a length of chain stitches that everything else gets built into. Get that first row of chains even and you've solved the problem that stops most beginners before they've made a single stitch.
The slip knot is the only part of the chain that has to be tight
A crochet chain is a series of interlocking loops pulled through one another, and the first of those loops is the slip knot. Make it by crossing the yarn over itself to form a loop, pulling a second loop up through the middle of the first, and tightening that second loop around your hook. The knot should sit snug against the shaft of the hook but still slide when you tug the working yarn. If it won't move at all, you've tightened it around the throat of the hook instead of the shaft, and your first chain will come out pinched and hard to work into.
Everything after the slip knot is a repeat: wrap the yarn over the hook from back to front, catch it, and pull it through the loop already on the hook. That's one chain. The loop you just made becomes the loop you pull through next time. The motion is small, and it stays small — you're not pulling the yarn taut, you're drawing it through with just enough tension that the new loop matches the width of the hook.
The mistake almost every beginner makes is tension, not technique. Holding the working yarn in a death grip produces chains so tight you can't insert the hook into them on the second row, and the problem doesn't show up until you try to work back across. Loosen your grip before you loosen anything else. The chain should look like a row of small V shapes along the top and a series of bumps along the back — if you can't see the Vs, you're pulling too hard.
Your hook size determines whether the chain is workable, not just how big it is
Chain stitches come out the width of your hook, so the hook you choose decides whether the foundation row is something you can actually get into. In the Craft Yarn Council standard system, a G-6 hook measures 4.00 mm, an H-8 measures 5.00 mm, and an I-9 measures 5.50 mm. A G-6 is a medium hook commonly used with worsted-weight yarn for beginner-friendly projects like basic blankets and hats. An H-8 is the size most often recommended for learning to crochet with medium-weight yarn, and it's the one to reach for if you're working a granny square or a simple blanket. An I-9 is larger still and gets used with medium to light bulky yarns when you want a looser fabric — baby blankets and beginner hats are the usual targets.
If you're working with crochet thread rather than yarn, none of those apply. Thread work uses steel hooks, and a steel size 1 measures 2.75 mm. That's fine for detailed work like lace edgings and doilies, but it's a bad place to learn a basic chain — the stitches are small, the thread has no give, and mistakes are harder to see and harder to undo. Learn the chain on worsted weight and an H-8 first.
Matching hook to yarn matters more than matching hook to pattern when you're starting out. A hook that's too small for the yarn gives you a dense, stiff chain that resists the hook on the return row. Too large and the chain looks airy and uneven, with gaps between stitches. If your chain looks like either of those, change the hook before you change your technique.
Counting chains is where beginners lose their place, and there's a fix
You need to know how many chains you've made, and the count is not the number of loops you can see on the front. Count the V shapes along the top edge, not the bumps on the back, and not the loop currently sitting on your hook — that loop doesn't count as a chain. This is the single most common source of a foundation row that comes out one stitch short.
The practical fix is to count in groups as you go rather than trying to count a long chain after the fact. Ten at a time is manageable; thirty is guesswork. If your pattern tells you to chain a number and then work into the second or third chain from the hook, know that turning chains are structural, not decorative — they stand in for the height of the first stitch in the row, and skipping them throws off the whole edge.
If you do lose count, don't guess. Pull the chain out and start again. Ripping back a chain is fast, and a foundation row built on a miscount produces a project that's wrong at the edges for its entire length. There's no way to fix that later without undoing everything above it.
The chain is the foundation for everything, including the shapes you actually want to make
A granny square starts with a short chain joined into a ring, with subsequent rounds worked into the center of that ring. A crocheted circle starts the same way, or with a magic ring — an adjustable loop that you tighten after the first round of stitches is in place, which closes the center hole completely. A magic ring is worth learning if you're making anything round where a visible gap in the middle bothers you, like a hat crown or an amigurumi piece. It's harder to execute than a chain ring and takes a few tries to get the tension right, but the finished center is cleaner.
A crocheted heart is worked flat, usually starting from a chain, with increases and decreases shaping the two lobes and the point. None of those shapes are beginner-first projects, but all of them start with a chain or a ring, so the chain is the thing to get right before you attempt any of them.
Half double crochet is one of the three basic stitches you'll work into a foundation chain, alongside single and double crochet. It sits between them in height, which means its turning chain is shorter than a double crochet's and longer than a single's. When you learn it, you'll be working into the third chain from the hook rather than the second. Get the chain right and the stitch has something even to sit in.
Changing colors in crochet is done at the end of a stitch, not at the beginning of the next one. You work the last pull-through of the final stitch of the old color with the new yarn, leaving a tail to weave in later. If you change colors before that final pull-through, you get a visible half-stitch of the old color at the edge. This applies to chains too — if you're changing colors at the start of a row, the turning chain is worked in the new color.
Speed comes from tension, and tension comes from repetition, not from a better hook
Beginners who chain slowly usually aren't slow at the motion — they're slow because they keep stopping to check whether the loop is still on the hook and whether the chain is even. That checking is what eats the time. Once your grip settles and you stop re-tightening after every stitch, the chain runs at a steady pace and the count stays consistent without conscious effort.
Practice chains are the cheapest thing in crochet. You can chain a yard of yarn, pull it out, and chain it again, and the yarn doesn't care. Do that until the tension is even before you commit to a project. The cost of skipping this is a foundation row that's tight at one end and loose at the other, which shows up as a wavy or pinched edge on the finished piece.
One thing worth being honest about: the chain is the least interesting part of crochet, and no hook or yarn makes it interesting. A hook with a ergonomic handle won't teach you tension, and a premium yarn won't fix an uneven foundation. The chain is a means to an end, and the end is the fabric you build on top of it. Get it even, count it correctly, and move on.