This is mostly what I do as well. However, I also kind of wiggle the selvage edges together until the folded piece is straight with no 'bubbles'. Lay flat and press again for a sharp crease on the fold. Cut one end and then flip to measure from that side. I find this works to get rid of the dreaded 'v' in the fold when cutting strips. Shown to me by a superb quilter at my LQS.

The last quilt I made had stripes on it.
Well, guess what, If I folded the material and matched the stripes on each end, it matched about half way down the fold, then it had a huge crooked fold from the middle to the end.
The material had to be crooked when they put the stripes on it.
They were about 2 inches off. So, took an inch off of the top right hand corner and about an inch off of the bottom left corner. It looks straight to me, however, I know its crooked, but you really can't tell. Next time I buy plaids or stripes, I will double check the directional material first.

Every one is in such a rush these days and everything has to be done fast. It is hard to convince people that the time spent prepping fabric, just like painting, takes a few extra minutes and makes a tremendous difference in the finished piece and in the ease of working with fabric that has less fraying and stretching.

These prepping methods are rarely taught anymore and it is a sad thing. As long as you are happy with your results there is no perfect way to get something done.

I am not a perfectionist but I do take my time and enjoy the doing.
peace

I have pulled to straighten fabric, esp. for garment sewing. Unless it is noticably off I don't for quilting.

Many, many years ago, when I first started sewing, I was taught to pull my fabric diagonally to straighten it before I started any cutting. I was making clothing then, so it was probably much more important so things would hang correctly. I no longer do it. I probably should, but I don't think it is as important in quilting. Today I just line up my selvages, trim to a straight side and start cutting.

I always square my fabric after I wash it. I use Leah Day's method. She has a video on her site that explains it easily.

Watson

Me, too. But I pay attention to straight of grain if it's severely off. Then I decide whether to use it or not...often not. It depresses me that some fabric today seems to have straight of grain flaws. Quality control is our friend.

This is what I do. The fabric can be off as much as 4 inches or more. I just trim the fabric back to the point where it is on grain.

First, though, I have to decide what is more important, having the fabric straight on grain or having the print on grain. Sometimes the print is off grain and if it is, I will cut the fabric even though I know it is off grain because the print will show up as whacky and you won't be able to match things up if that is what you want to do.

When squaring-up fabric for cutting strips off yardage, I always square-up from the fold in the middle of the fabric. That way, there's no "V" at the fold when you open the fabric. It doesn't really matter what the selvedges or raw edges are doing.

I also do it this way. Comes from garment sewing.