
I don't even knit.
The paired needles have been set aside for that hypothetical day on which I suddenly overcome my aversion to knitting, but I still had a large number of mismatched and broken ones. It didn't seem right to throw them out without investigating possible uses, so I went to my good friend Google and asked for ideas on repurposing knitting needles.

Why not use knitting needles as stems for crochet flowers? It would look silly if all the 'stems' were dead straight, but the ability to bend those stems a bit would allow much more scope for arranging. (I guess it would be more appropriate to make knitted flowers, but crochet is my natural default).
I sorted through the pile of mismatches to see what I had to work with, and played around doodling arrangement designs until I came up with something I liked. Given that I have no expertise whatsoever in either drawing or flower arranging, this took a while. Once I had a 'design' I thought I could replicate, I dug out a few odds and ends of yarn for use on flowers and leaves.
For the main flower I followed this lovely rose pattern, though I used a medium weight wool and a 4mm hook, seeing that I wanted quite a large flower. Actually I miscounted my stitches somewhere along the line, so I ended up with a couple more petals than I was supposed to have. It looked alright though, so I left it the way it was and moved on to the other flowers.

The leaves are all different sizes, but were made in much the same way as the flower petals, i.e. a combination of stitches increasing then decreasing along each side of a central spine, attached to a base ring that grips onto the needle stem. I've included a basic pattern below - this is for a leaf the same shape as the flower petals, but you can change the size and shape very easily, by lengthening the chain or experimenting with the combination of stitches used to shape the leaf.
The next step was to bend some of the knitting needles into 'stems'. I approached this part with some trepidation - if I didn't manage to shape the needles the way I wanted, I might have had to scrap the whole project - but it turned out to be very easy. The plastic softens in boiling water almost immediately; all you have to do is fish the needle out with a pair of tongs, bend it into shape and hold it for a short time until it cools.
Most of the needles I used were red, green or brown, in keeping with the overall colour scheme, but I decided to include one typical grey needle, just to emphasise the knitting needle theme of the arrangement. I made a little twist in this one by winding it around the handle of a wooden spoon.
The final step was to fill a vase with floral foam and arrange my flowers. It didn't turn out quite the same as my 'design', but I was happy with it.
So, in short, I get given a bunch of knitting needles, and my immediate reaction is to make something out of the ones that can't be used for knitting. I suppose the next thing is to employ some of the usable ones for the traditional purpose, and actually knit something. That'll be interesting.
Crochet flower with knitting needle stem

Hook: a suitable size to make reasonably snug stitches in the yarn you're using.
Stitch marker
Old knitting needle for flower stem
Ch5, sl st to make a ring.
The base cone is stitched in continuous rounds, adding 2 stitches per round until you have a cone that is 15 stitches around. Use a stitch marker to keep track of rounds.
Round 1: 5sc in ring (5st)

Round 3: 2sc in first st, 1sc in next 3 st. 2 sc in next st, 1 sc in next 2 st (9st)
Round 4: 2sc in first st, 1sc in next 4 st. 2 sc in next st, 1 sc in next 3 st (11st)
Round 5: 2sc in first st, 1sc in next 5 st. 2 sc in next st, 1 sc in next 4 st (13st)
Round 6: 2sc in first st, 1sc in next 6 st. 2 sc in next st, 1 sc in next 5 st (15st)
Round 7:*Ch8, then 8 sc down the spine of the chain. sc in the next 3 stitches. Repeat from * five times.

With new colour, sl st between chains
*Make the following stitches up the 8 stitches of the chain:
hdc; dc x 3; hdc x 2; sc; sl st. ch3.
Reverse the order of the stitches down the other side of the chain:
sl st; sc; hdc x 2; dc x 3; hdc.
sc 3 st together between petals
Repeat from * 5 times. Fasten off and weave in ends.
Thread knitting needle through cone for 'stem'.
You can change the look of the flower with longer chains or different combinations of stitches to shape the petals.
Leaf to grip onto knitting needle stem
Ch5, sl st to make a ring.
sc in each sc around
Ch8, then 8 sc down the spine of the chain. sc in base ring.
Turn, and make the following stitches up the 8 stitches of the chain:
hdc; dc x 3; hdc x 2; sc; sl st. ch3.
Reverse the order of the stitches down the other side of the chain:
sl st; sc; hdc x 2; dc x 3; hdc. sc in base ring.
Fasten off and weave in ends.