How To Do Corner Start Diagonal Crochet

This method of crocheting is done diagonally, corner to corner.

Difficulty: Average

Time Required: 20 minutes to learn technique

Here's How:

1. Row 1: Chain 5, turn, 3 double crochet in the 5th chain from the hook (beginning block made).
2. Row 2: Chain 5, turn, 3 double crochet in the 4th chain from the hook (block made), slip stitch around post of beginning chain of previous block, chain 3, 3 double crochet in the same space where slip stitch was made (around post of chain). This row now has 2 blocks.
3. Row 3: Chain 5, turn, 3 double crochet in 4th chain from hook (block made), slip stitch around chain-3 post of first block, chain 3, 3 double crochet in same space * slip stitch around chain-3 post of next block, chain 3, 3 double crochet in same space *.
4. Remaining Rows: Work as in row 3, repeating between stars (*) as many times as needed across row. There will be one additional block at the end of each row. When desired width is reached, see step 5 (Decrease Row).
5. Decrease Row: When desired width is reached, begin decreasing, as follows: Slip stitch in each of first 3 double crochet and in first chain-3 space, chain 3, 3 double crochet in same space, * slip stitch around chain-3 post of next block, chain 3, 3 double crochet in same space * , repeat between stars (*) across row, end with slip stitch around chain-3 post of last block.
6. Repeat Decrease Row until only one block remains.

Tips:

1. You can make an afghan in diagonal crochet by making one large square of the size desired or, for take-along work, you can make smaller squares (perhaps in varied colors) to join together when finished.
2. Where above directions say "slip stitch around chain-3 post", an alternate way of giving these directions would be "slip stitch in chain-3 space".

Source - About.com