This is my version of the original Englipedia activity.
First, I ask the students if they know what "find" and "someone" mean. Then I demonstrate how the activity works by writing the first three items from the worksheet on the blackboard:
I ask the JTE to fill in the blanks and tell them that I'm going to find a student who the sentence would apply to. For example, if the first sentence is "Find someone who likes chocolate," I ask a student in the first row "Do you like chocolate?" and if they answer "Yes, I do," I write their name next to the sentence on the blackboard. I would advise asking students whose names you can remember or who are likely to give the answer that you're looking for!
Once the students have the hang of the idea, I pass out the papers. If most of the class can write all seven sentences then that's great, but that might not be feasible in every class, so I try to make sure that the students have completed at least the first three pre-constructed sentences. When most of the students have written a decent amount, I ask them to pass their papers to the front of their rows so I can gather all of the papers and then shuffle them.
I pass the papers back out again, making sure not to give a student their own paper. The papers are now a list of directions to the student who received it. They have to find one of their classmates who match each sentence and sign their name. Sometimes this is easy and sometimes it's quite difficult, but usually the students enjoy trying to find other students who match the sillier criteria that their classmates have come up with.
After 5 or 10 minutes, I call time and ask the students to sign the bottom of the paper (the "found by" section) and return the paper to its original owner.
The instruction sentence is technically a relative pronoun sentence ("a person who...") but it doesn't really have the students constructing original sentences based on the grammar pattern, so keep that in mind. You can adjust it to other grammar patterns by altering the sentence, like "This student likes chocolate:" or something along those lines.