Straight vs diagonal for plaids
 

I have a bunch of plaid shirts all disassembled, starched and ready to go. I'm trying to decide on the pattern and i have it (tentatively, lol) narrowed down to this one http://pinterest.com/pin/33411086609...ce_app=android or this one http://pinterest.com/pin/Af5C-s-GXWJ...ce_app=android or this one http://pinterest.com/pin/33411086609...ce_app=android . So, 2 questions: which one do you think would be best to try for my first pieced quilt, and is there any standard for using the plaids straightwise or diagonally?
Thank you for taking part in my research survey, lol.

I like the second one best. I would not cut anything on the diagonal(bias). Have you checked out Bonnie Hunters site. She has some nice plaid ones on there.

You mention that this will be your first pieced quilt. Given that, I would also go with the 2nd option. No HSTs or foundation piecing. As far as lengthwise or diagonal, I've probably seen them both ways. Your quilt, your design choice, although going back to your '1st pieced quilt' statement, I would go with on grain even though you've starched them. I love recycled shirt quilts! Please post a photo when you are done.

In the first picture, the fabrics themselves are not cut on the diagonal. The blocks may be string pieced on a foundation, or perhaps strip pieced and then cut into squares on the diagonal. I like that design best, but I agree that the second design would be easiest.

I like the second one, too! I was gifted with a bunch of "man" fabrics and this will be a great pattern for me!

If I had men's plaid shirts all prepared and ready to go, I'd use this nifty pattern (See link. It's a tutorial). If you want this quilt bigger for a bed sized quilt, just use more shirts and make more blocks. This pattern is on my to-do list. I like how the author gives instructions for how to cut the shirts. If your fabric is starched before you cut your pieces, and you are carefully sewing, without pulling the fabric (to stretch it), and you are carefully ironing, without dragging the iron across the fabric (to stretch it), then the bias situation is not so difficult to control. The key is to pick a pattern you like, so you will enjoy the quilt. It's not fun to put a lot of work into a quilt only to be not happy with the pattern you chose.
http://wishesandweeds.com/seven-shirts-quilt/

I agree 1st one looks a little harder,ask if all squares are same size , I've just varied direction of plaid, taken smaller pieces made 4 patch and added those, all kinds of ways. Just lay them out and make it your own!!!

Definitely the 2nd one!

Pattern for Plaids
 

I like pattern #2. I did an all plaid quilt for my husband. I used the Disappearing 9 Patch and it turned out very nice.

I had an answer until I saw the part 'my first pieced quilt'. Whatever pattern you choose, I would suggest doing it on a diagonal. Trying to line up assorted plaids and not make them look off is tricky. But, on a diagonal, they already are wonky so it doesn't usually mess with your eyes. If the plaids are all really different sizes and patterns, really consider sashing to let the eyes rest. I didn't look at your patterns because I wanted to give you some general advise. Whatever you choose, try a couple sample blocks before jumping it. Especially with Pinterest, they could be more difficult than they appear.