I've been making them out of various types of rags for the past month, then ordered some made of french linen, only to find that my pup is a bit too small as of yet for them (what I thought was circumference turned out to be width). I don't want to order again for a while (pissed off at the postal service for the moment, it took a week for my order to get to me), so...

What materials on hand is ideal for making your own tug toys out of? Ideas, anyone?

how old is your dog, he might not even need a tug yet, try a shoe repair shop in your area and get a piece of tanned leather, or a small rag-towel instead if they are that small they most likely dont have to be on a tug yet anyways.

If you can find a burlap sack, you can cut appropriate sized tugs out of this material.

Jute is the typical material of bite sleeves/tugs, but it seems impossible to find outside the working dog world. Burlap is closest and you might find it at a farm and ranch supply store. They use it for feed bags- or they might know where to find some...I found some rolled retriever toys made from burlap at a pet store that I used for awhile until they frayed and tore but my pup had fun tugging them to shreds! Leather will tear or slip easier with a older pup.

You can also purchase a welders apron. They are really cheap and you can cut the pieces into whatever size your heart desires. They seem to last forever.

I made my tugs using 3 different materials
a) burlap from feed bags at CAL Ranch stores. I used it in double layers because it did fray alot and sewed it around a folded sheet of felt rolled up. This gave the tug some shape and integrity for pulling and yet was still soft enough for the puppy teeth. Remus loved these ALOT while he was still young. I think he was born with burlap in his mouth!!!!
b) chamois material , fr auto section in Walmart stuffed with strips of used bed sheeting when we were ready to move on to something a little more sturdy. These worked great for awhile but he out grew these very quickly. The material doesn't have very good strength when pulled on.
c)8 oz horsehide. Leathers are graded in thickness by the oz. I found the 6oz was too thin and ripped too quickly. I made several tugs using the 8 oz (fr saddle/horse supply store in their scrap box for cheap!!) rough side on the outside, double thickness nylon strapping from CAL Ranch for the loops and stuffing them as hard as I was able with strips of used bedding. These stood up to the wear and tear of training just as well as the jute tugs I bought online.
Since I was doing my own sewing I used varying lengths for the tugs , as well as using 1 or 2 loops for the handles. Because Remus loved the fight in the tug-0-war I found the stronger the tug the better. Using the double thick nylon strapping made the most comfortable handles I had to work him with. A tip: depending on how you sew them the loops will stay open all the time and make it even easier to work with during training.
It was using a custom tug 6"wide X 18" long that we were able to train Remus to out the sleeve while still on the decoy. Coming back to me for a good fight on a fat tug was worth outting and this was the only time he saw the fat tugs so they became special really quick.

She's 4 months old. How far ahead should we be? I've had her on a backtie and most times she knows to target the rolled-up rag if held on both ends and pull back, which was why I thought she was ready for tugs. Should I wait till her adult teeth sets in?

I was using burlap I got from the hardware store as well, but the weaving is really loose and it got caught in my pup's teeth way too easily, which hurts her if she pulls too hard.

I'll try the chamois. Don't know where I can get leather though--I'm in the middle of the city.

Has anyone tried denim? maybe only for pups or heavy denim?
Seems to work well when they latch on to my jeans!

Another thought have a look in the fabric stores for heavy wt cotton -- canvas. I think it is the material the training tugs for hunting labs are made of. Then you can choose how hard it is stuffed.

Denim was too smooth and my pup couldn't get ahold of it if stuffed.