To stay fresh, constantly experiment.
For the past couple of days I've been experimenting with rust marks on paper and on fabric. I tried first on fabric without any instruction and had a little success but nothing really worthwhile.
While the first batch was sitting in vinegar water I did some sorting of magazines and articles I had saved. Some got pitched but some were saved and what to my wandering eyes should appear -- an article on rust spots. Aha -- I had been doing it wrong!
Armed with instructions I started over using tea for rust on paper and vinegar for rust on fabric. The vinegar on fabric worked beautifully.
First I put the fabric in vinegar, rung in out and layed it on my waxed paper. I have a stash of rusty nails the were perfect for this piece of fabric, they were layed out on half of the piece, then I folded the other half over the top and carefully rolled it up. Once rolled I wrapped string around it to secure it then placed it on our kitchen radiator. Once it was dry I unwrapped it and ironed it. Happy with this so I did a few more pieces.
The tea -- well it didn't turn out like it was suppose to but it wasn't a total loss. Here's a sample --
For this I used paper in two different sketchbooks. One with heavy watercolor paper and the one above is paper that has a smooth finish and is not as heavy as the watercolor paper. I placed the rusty items on the paper and then covered with wet teabags. Waxed paper was placed wrapped around the page so the water from the teabags didn't run all over when I closed it up and clamped it closed.
I used the same process for the other sketchbook and this is how that came out --