Crocheting a dress start to finish means working a swatch to find your gauge, choosing a pattern sized to your actual measurements rather than your ready-to-wear size, crocheting the bodice and skirt as separate pieces or in one piece from the top down, joining them with seams or a continuous round, and blocking the finished garment so the stitches relax into their final shape.
That's the whole arc. Everything below is the detail that makes the difference between a dress you wear and a dress that sits in a bag because the waist sits wrong or the skirt grew two inches after washing.
Learn the basic stitches before you commit to a dress
A dress is a large project built from a handful of stitches, and you need fluency in four of them before you buy dress quantities of yarn: chain, slip stitch, single crochet, and double crochet. The half double crochet is the fifth you'll want, because it sits between single and double in height and gives a denser fabric than double crochet without the stiffness of single — many dress patterns use it for the bodice where you want coverage without bulk.
To start a crochet chain, make a slip knot, put it on the hook, wrap the yarn over the hook from back to front, and pull that loop through the loop already on your hook. That's one chain. Ten thousand of these make the foundation of a skirt worked flat. To half double crochet, yarn over, insert the hook into the next stitch, yarn over again, pull up a loop — you now have three loops on the hook — then yarn over one more time and pull through all three at once. It's a three-loop decrease to one, which is why it works up faster than single crochet and drapes better than double.
Practice on a medium hook. A G-6 is 4.00 mm in the Craft Yarn Council standard system and is commonly used with worsted-weight yarn for beginner projects like basic blankets and hats. An H-8 is 5.00 mm, also widely used for learning with medium-weight yarn and for granny squares and simple blankets. Neither is the right hook for a dress yet — you'll pick the hook from the pattern and your swatch — but either is the right hook to learn on.
Working in the round comes next. To crochet a circle, chain four, join with a slip stitch into the first chain to form a ring, then work your first round of stitches into that ring rather than into individual chains. To crochet a magic ring, wrap the yarn around your fingers to make a loop, work your first round of stitches into the loop itself, then pull the tail tight to close the center. The magic ring gives a closed center with no hole; the chain-ring method leaves a small gap. For a dress, the magic ring is worth learning because it's the standard start for the crown of a top-down yoke or for decorative motifs.
Swatch, and treat the swatch as the real answer
Your gauge determines whether the dress fits, and the pattern's stated gauge is only a starting point. Work a swatch at least four inches square in the stitch pattern the body of the dress uses, wash it the way you'll wash the finished dress, let it dry flat, then measure the stitch and row counts across the middle of the swatch — not at the edges, which curl and lie. If your stitch count is higher than the pattern's, your fabric is tighter and the dress will be small; go up a hook size. If it's lower, go down.
This is where most first dresses fail. A dress has far more stitches across than a hat, so a small gauge error multiplies into inches of difference at the bust and hips. A swatch that's off by half a stitch per inch across a forty-inch bust is twenty stitches of error — a full size or more. Do the swatch, and do it in the round if the dress is worked in the round, because working in the round and working flat give different gauges in the same hands.
The trade-off is time. A washed and dried swatch costs you an evening before you've started the dress. Skip it and you may spend three weeks on a garment that doesn't fit. The swatch is cheaper.
Choose a construction and a size that matches your measurements
Most crochet dress patterns fall into three constructions: top-down in one piece, bottom-up in one piece, and seamed from separate bodice and skirt panels. Top-down lets you try the dress on as you go and add length or shaping without ripping, which is why it's the friendliest for a first dress. Bottom-up is easier to get a clean hem on but harder to adjust at the bust. Seamed construction gives the most structured fit and is the right choice for a fitted sheath, but it costs you seaming time and the seams show if your tension wanders.
Size from your body measurements, not your clothing size. Measure your bust at the fullest point, your waist at the narrowest, and your hips at the widest, and compare each to the pattern's schematic — the finished measurements, not the "to fit" numbers. If you fall between sizes, size to your bust for a top-down dress and to your hips for a bottom-up one, then adjust the other end with increases or decreases. Crochet fabric has more give than woven fabric but less recovery, so a dress that's slightly too tight will stretch and stay stretched, while one that's slightly too loose will hang.
Work the bodice, then the skirt, and manage the transition
In a top-down dress, you start at the neckline, work the yoke in the round with increases at four points to shape the shoulders, then divide for the armholes and work the bodice even until you reach the waist. The waist is where you decide the silhouette: work even for a straight dress, decrease for a fitted waist, or switch to a larger hook for an A-line flare. Switching hook size is the quiet trick for shaping in crochet — a G-6 at 4.00 mm for the bodice and an I-9 at 5.50 mm for the skirt gives you a fabric that opens up below the waist without changing stitch count as dramatically.
For the skirt, work in the round and place your increases evenly around the circumference rather than at the sides, or you'll get visible ridges. If the pattern uses a stitch pattern with a repeat, your increase rounds have to fall on the repeat or the pattern breaks. Count the repeat once at the start and write the number on a sticky note attached to the pattern.
Changing colors mid-dress is the same skill as changing colors anywhere: work the last stitch of the old color until two loops remain on the hook, drop the old color, pick up the new, and pull the new color through those last two loops. Carry the unused color up the inside of the work if the stripes are close together, or cut and weave in if they're far apart. Carrying across more than a few rounds shows through on a dress, which is lighter-weight fabric than a blanket.
Seam, finish, and block — in that order
If you're seaming, use a whipstitch or mattress stitch with the same yarn or a smooth matching thread, and work the shoulder seams first, then the side seams from hem to underarm, matching stitch for stitch. A mattress stitch seam in crochet is nearly invisible from the right side, which matters on a dress in a way it doesn't on a blanket. Weave in every tail as you finish each section, not all at the end — a dress has a lot of tails, and loose ends that get caught in a seam are a nuisance to fish out later.
Blocking is not optional on a dress. Wet-block it: soak in cool water with a wool wash if the fiber allows, roll in a towel to remove excess water, then lay flat to the pattern's finished measurements and pin the hem and any lace edges. Blocking opens the stitch pattern, evens out tension variations, and sets the final length. Expect the dress to grow slightly in length as the stitches relax — this is normal and is one reason you swatched and washed before you started.
One note on the finer end: if your dress has a lace overlay, a thread-weight trim, or a detailed edging, you may find yourself reaching for a steel hook rather than a yarn hook. Steel hook size 1 is 2.75 mm in the Craft Yarn Council steel hook standards and is used with crochet thread for detailed work like lace edgings and doilies. It's also the size to consider for a fine cotton dress worked in thread rather than yarn, where the fabric needs to be dense enough to hold shape without lining.
Finally, if any part of the dress involves a lining or a sewn-in closure, you'll be at a sewing machine, and machine needle sizes run NM 60 to NM 130 per the Schmetz Needle ABC guide — a light needle for a fine cotton lining, a heavier one for a structured bodice lining in a firm woven. Crochet dresses that need a lining are usually the fitted, thread-weight kind, and that's a different project from a worsted-weight pullover dress. Know which one you're making before you buy the yarn.