Best way is to put the stuff in a spot where people are sitting right on top of it but where don't expect somthing.
So do not put it behind your clothes or in a too nice looking jewelry box. But put it in the couch they are sitting on or in the double isolated coffee cup where they are drinking from.
Like the movie where someone sneaks some diamonds through the customs in his cola can. While they strip searched him to find the diamonds, he asked the customs officer to hold this can, and they still didn't notice.