This Personal Impressions Zendoodle Trees stamp is ideal for zentangling.
Any simple stamp with large plain areas can be zentangled (they can also be stamped onto patterned paper and paper pieced).
I like the fact that each tree is already divided into interesting shapes which sometimes help with ideas for a suitable zentangle pattern. Some of the patterns I drew were ideas I had seen online, and some grew from the shape that they had to fill - such as the triangular shapes in the tree to the far right.
Once I had finished zentangling, I cut out the stamped image leaving a narrow white border and stuck it to red mirricard. I then decided to use a Spectrum noir pencil which matched the background to pick out some of the zentangled details. I matted the red mirricard onto white card and then onto black leaving a narrow border. The whole thing was stuck onto an A4 card folded in half (A5 landscape); a small peel off greeting was the finishing touch - coloured red to match the key background colour.