I picked rip, but still firm tomatoes, with no blemishes.
I halved them and placed cut-side up on a baking sheet (lined with Magic Liner), and sprinkled lightly with salt.
I then put this tray into the simmering oven (or the lowest oven setting) for about 10 hours, until the tomatoes were dry, but before they were completely leathery.
The tomato flavour really intensified. we ate several of these fresh from the oven, and the rest livened up a batch of passata. Next time, I'll try packing some into oil, and see how well they keep.