The triple crochet results in a looser pattern because it is taller.
1. Make a chain of desired length, unless there is already a row.
2. Place yarn over the hook twice before inserting hook, into 5th chain from hook (not counting the loop on hook).
3. Place yarn over hook again and draw yarn through on loop. There are now 3 loops on hook.
4. Place yarn over hook and draw yarn through 2 of the loops on hook. There are now 2 loops on hook.
5. Place yarn over hook and draw yarn through both loops on hook, completing one triple crochet.
6. To continue row, place yarn over hook twice, insert hook into next chain and continue triple crochet steps above.
7. For another row, at end of first row chain 4 and turn work. This ch 4 counts as the first triple crochet of next row, so begin triple crochet stitches in 2nd stitch of previous row. To keep work even, work last triple crochet of the row in the 4th chain of turning ch 4 at end of previous row.
How to work treble crochet - "tr"
Ch required length.
Step 1 - Y O twice, insert hook into 4th ch from hook, draw yarn through - 4 loops on hook - , y o draw yarn through 2 loops - 3 loops on hook - y o, draw through 2 loops - 2 loops on hook - y o, draw through 2 remaining loops - one tr made. Work one tr in each remaining ch.
Step 2 - Ch 4, turn work 1 tr in 2nd st from hook and in each remaining st inserting hook under both strands of st unless otherwise specified. Repeat step 2 for desired number of rows.
NOTE: Turning ch is counted as first st of each row.
Source: Crochet Primer, Bernhard Ulmann Volume 64