I have a large number of driveway markers used during the winter to indicate the boundaries of a driveway to the snow plows. Usually, during the summer, these sit idly in my garage. However, this year I got into gardening and decided they were a perfect way to support my tomato plants.

You can buy these pretty cheaply on Amazon https://www.amazon.com/Driveway-Marker-Reflective-Diameter-Fiberglass/dp/B01J8TV0TS (not a referrer link)

Use the coupler to join two stakes together, which will provide you with 8' of support. When coupling, slide the coupler over the non pointy end of one stake, and slip the other non pointy end into the other end of the coupler. I typically put a piece of duct tape to make sure nothing moves around.

Then use the clips to hold your plant to the marker. I use a mix of small and large clips depending on the size of the stem I am supporting.