Crossed Double Crochet.

Use smooth, plainly coloured yarn, a suitable hook and two removable markers. Choose a combination that lets you find the stitch tops without stretching the fabric. The double crochet lesson covers the yarn-over and two pull-through stages used throughout this exercise.

You’ll practise on a twelve-stitch row. In this sample, the starting and turning chains count as one stitch at the edge.

Chain fourteen. Work a double crochet into the fourth chain from the hook, then one into each remaining chain. The three chains skipped at the start count together as the first double crochet position.

You have eleven actual double crochets plus the counted starting chain: twelve positions altogether. Mark the top of that starting chain and the last actual double crochet. Count both marked edges before continuing.

For this exercise, chain three at the start of each later row also counts as the first double crochet. Do not add a stitch into its base. Another pattern can use a different turning-chain convention.

Chain three and turn. That chain occupies position one of the new row, above the last stitch of the base row.

Number the old row's twelve positions from the end where you are now working. Leave position two unworked for the moment. Yarn over, insert under both top loops of position three, and complete one ordinary double crochet.

Pause here. Position two is still waiting, while position three now holds the first new stitch of the pair. There is no chain between the pair's two stitches.

Yarn over. Take the hook behind the double crochet you just completed, and reach the waiting stitch at position two. You can tip the new post forward gently to expose that insertion point.

Insert from front to back under both top loops of position two. Draw up a loop, yarn over and pull through two loops, then yarn over and pull through the final two loops.

The return stitch lies behind the first new post when viewed from the side you are working. The hook entered the old stitch's top loops. It did not go around that old stitch's post, as a front-post or back-post stitch would.

You have made two new stitches using two old positions. Keep one active loop on the hook, and let the pair relax before finding the next two unused positions.

Work the remaining pairs into these old positions, in order:

• Position five, then position four, returning behind the first new post.
• Position seven, then position six, with the same behind-the-post return.
• Position nine, then position eight, again using each top once.
• Position eleven, then position ten, completing the fifth pair of the row.

Work one ordinary double crochet into position twelve. This last position is the top of the previous row's counted starting chain. Do not leave it out because it looks different from the actual double crochet tops.

You should still have twelve stitches: the chain-three edge, five crossed pairs and the final double crochet. Each base stitch has been used once.

Chain three and turn. Skip the old stitch at its base, because the chain represents the first new stitch. Work one double crochet into each remaining position, including the top of the old row's starting chain at the far edge.

Count twelve positions again. This plain row lets you inspect the new tops produced by the crossed pairs without having to cross another pair immediately. You can alternate the crossed row and this plain row for a small practice piece.

Keep the crossing method consistent on each crossed row. Turning changes which fabric face is towards you; it does not turn an instruction to work behind a post into permission to wrap around it.

If a gap remains where a stitch was skipped, check whether you returned to that position. A pair is incomplete until both old positions have been used.

If the row grows, look for a double crochet accidentally added at the base of the counted turning chain, or a pair worked into an already used position. Undo the affected section instead of disguising the extra top at the edge.

If the pair bunches, relax the working loop and check your route behind the first post. Pulling that post tightly aside makes the waiting stitch harder to reach. Changing hooks is not a substitute for correcting a missed or reused insertion point.

Keep the crochet glossary nearby for abbreviation checks. If the double crochet movements feel awkward, practise a plain row before trying the crossing again.