A riding lawnmower is certainly the lowest cost powered tug, especially if you can find a used one with mower deck problems. Those go for really low prices. They aren't very portable though.

If you have a riding lawn mower with an attachment point for a trailer hitch, but no access to your own welding shop, this tow bar will work well:
https://www.aerospecialties.com/aviatio ... -capacity/. The problem with this arrangement is that there isn't enough room in most T-hangars to get the lawnmower and tow bar behind the airplane when it's facing out.

Although it was expensive, I like my Best Tugs A-3 electric tug.

I coast into my hanger and tow out backward, it is not a t hanger however.

I use to use a figure of 8 motorcycle strap that I would wrap around the leaf spring and run the loop through itself, then hook it to the winch and it would pull the plane right in no problem. On off in a few seconds. It did not slide or affect the springs. I doubt it would damage the leaf spring if you compare the minimal amount of pull on the spring compared to a landing.