We used welded wire fencing to make cages. It works well and is much more durable than other materials. EP

What kinds of plants are you looking to support? Vines? Clumpers with heavy blooms that need to be supported on all sides? Tall, thin-stalked plants (like lilies) that will fall over unless gently hooked to something?.......

concrete underlay, metal coathangers, tomato cages, sticks and baling twine, pvc pipe

At several English gardens I saw neat supports that were "constructed" by shoving limber branches around plants, joining them at the top, maybe by wiring them, and then weaving vines through them for support. They ranged anywhere from 1 foot to 5 feet tall. When the plants were mature, you couldn't see the supports. I liked the look so much I took several pictures of them so I wouldn't forget the idea. They also stuck sicks in the ground about 12" apart at the front of borders and then wove other sticks through the upright ones for a neat, natural looking border fence.

I'll second (or third?) tomato cages. The former owner of this house left stacks of them! They can be cut in half too. I've done that to hold sunflowers up against a fence (when I didn't want to shorten them), simply by driving the cages in deep or lashing them to the fence.

Old baskets can work in a pinch with smaller plants. Most will last at least one season outdoors and will disappear if the plant is leafy/flowery enough.

Fleur - do you happen to have pics of those supports, that you can post to the forum?