I use the lines on the ruler, and make sure that I cut on different sections of the mat.

I only use the lines on the ruler for cutting, but I will use the lines on the mat for lining up cut strips I'm going to subcut with the stripology ruler.

As to cutting up old mats, I've run them through the table saw. I use the blade DH uses for cutting PVC pipe. It's not anything special, just not precise anymore. He'd be very upset if I used his $$$ finish cutting blades. Just like I'd skin him if he used my dressmaking shears to cut up an old plastic tarp.

I use the ruler and make sure the line is on the fabric before cutting.

If you only take the line of the ruler up to the fabric, it can result in a short cut on the fabric.

I use the lines on the mat to line up the fabric fold so it is straight.

I use the rulers to cut with mostly. If it is a big cut, I will use one of the marks on the mat to line up the cut edge. I do have a 15.5 inch square ruler so I can go pretty big with the ruler and I have also two rules to measure butted up sometimes. One trick I learned with the rotary cutters is not to tighten them too much. If you adjust the screw so it is tight enough so the blade doesn't wobble but loose enough that the blade turns easily as you push it along that mat....that is good. You don't want to have to use a lot of force to just get the blade to turn without doing any cutting. Oh, and new blades are good. I try and get mine in the multi packs when they are on sale. My local chain stores keeps the multi-packs locked up so sometimes I have to ask if they have any.

Ruler only to measure. I use the blank side of my mat to cut on.

Yeah I learned about getting rid of batting fuzz on the good side of the mat the hard way. Evan after I thought I had it all off, I still would get some.

Check your cutter. Take it right apart. I found that one of my Fiskars cutters was cracked where the shaft meets the cutter body, and the blade was wedged into that crack. It would cut, like an exacto knife will cut, but it wasn't rotating. That was what was causing the damage to my mat. I threw it away and bought a new one and a new mat.

I change blades at first skip and don't use much pressure to cut. I cut the fabric not the mat. Using a weighted rotary cutter like Quilter's Select works for me. Not much pressure is needed. Buying new blades or a new mat equals out so it's personal preference. I have taken classes from many top notch quilters who use the mat line for cutting if they aren't promoting a ruler brand. When I see a mat on a good sale I buy it. I stack them on my cutting table (right now I have a stack of three) and rotate from top top to bottom and turning the mat when I think of it. I'm always using a new mat this way for a very long time.

I use both the lines on a cutting mat and the ruler lines for measuring.

Sort of depends on the size of the pieces.

It's not the blade as I've trained myself to change at first skip. I think it's the mat but it went in the center and I primarily use it to trim 4.5 to 8.5 blocks. how are the sides good and the center is gone? It's a rotating mat and it's one that rotates easily. A bit of sleuthing on the internet this brand is known for this. More sleuthing and I have decided to buy a big .double-sided mat and cut it into small sections. The really annoying part is it is the same brand as the one big one i have had for six years and have not even turned over. Go Figure. I am going to contact company but I want this spinner - it works. Thanks for all the suggestions I'm going to adopt turn the mat frequently as it is square.