straight edges in crocheting

Use the Chainless Starting Stitches to Give Your Crochet a Perfectly Straight Edge! | Yay For Yarn - YouTube

Crochet STRAIGHT EDGES in Rows Every Time - Easy Formula - YouTube

The first video shows without the turning chains. The second video shows that after you have 2 loops on hook for a sc you pull the yarn through one time ; for a hdc after you have the 3 loops on hook you pull the yarn through one time so she only chains one for a sc or hdc row. For a dc after the 3 loops are on the hook you pull the yarn through twice so she chains 2 at the beginning ; for a triple crochet after the yarn over twice (which is 4 loops on hook) it's pulling yarn through the 2 loops 3 times so she is figuring a chain 3 at the beginning of row for a triple crochet.

I chain 2 for a dc but maybe 1 chain for a dc is enough or maybe it would be better to do chainless rows like the video above? or just follow the pattern and if it says to chain, then chain at the beginning of rows.