There's always the traditional technique - leave a trail of bread crumbs.
Bad idea, it was the breadcrumb trail that resulted in Hansel & Gretel not being able to find their way home
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After reading the Grimms' fairy tale, I always thought it was odd that the breadcrumb trail made it into our culture as an idiom when the story so clearly showed such a trail was useless (the forest animals ate them before the kids were able to follow the trail home, resulting in their capture by the witch).