Maggie, you are right - practice makes perfect. I have been knitting 39 years and even now, sometimes the row where I twist the cable is tight. And the wider the cable, the tighter it tends to be. But a 6 stitch cable, which is what you are doing, shouldn't be too tight. Keep practicing, and make a conscious effort to relax, especially on the row BEFORE you twist the cable, and you'll get it.

And it will look tight for a couple of rows, but then it will puff out as you do additional rows.

Are you doing purl stitches immediately before and after your cable? That will set off the cable and make it stand out.

Your stitch set-up might look like this, just as an example:
knit 10; purl 2; knit 6; purl 2; knit 10

How many rows are you working between every twist?
Years ago when I did my forst cable I did a twist every knit row....made for a very tight cable!
And are you putting the extra sts. on the cable needle after you work them? That will also make a more relaxed cable.
Linda C

the tightness will loosen up after you have some practice. but #7 needles are kind of small and will make a small cable. but cables are usually the knit stitch on a field of purl stitches. if your pattern calls for the cables to
be on the knit stitch side of the fabric they won't stand out very much at all and will look more like a large twisted stitch. Check your pattern to be sure you have the cables on the correct side of the fabric.

Better yet, practice making cables by making a scarf with some scrap yarn.

using #10 needles

cast on 28 stitches

row 1: k4,p6,k8,p6,k4
row 2: k10,p8,k10
row 3: k4,p6,k8,p6,k4
row 4: k10,p8,k10
row 5: k4,p6,k8,p6,k4
row 6: k10,p8,k10
row 7: k4,p6,k8,p6,k4
row 8: k10,p8,k10

okay here comes the big twist

row 9: k4, p6, slip 4 stitches onto the cable needle
(or a double pointed needle) hold these stitches
to the front of your work, knit the next 4 stitches
onto your regular needle, then knit your 4 slipped
stitches onto your regular needle,p6, k4.

row 10: repeat row 2
row 11: repeat row 3
row 12: repeat row 4
row 13: repeat row 5
row 14: repeat row 6
row 15: repeat row 7
row 16: repeat row 8
row 17: repeat row 9

continue in this manner until
your scarf is long enough and you know how to cable.

if you hold the slipped stitched to the front of your fabric the cable twists one direction. if you hold them to the back of the fabric the cable twists the other way. if you switch back and forth with eact cable you get a wigglely snake effect.

scarfs are a good way to learn a new pattern/knitting skill
because you can do just that thing until it makes sense to you-- and you've worked out any issues. you use up scrap yarn and have a quick little present for someone (kids always need a scarf and are tough on them), or you can donate it to a good cause

have fun

diggerb