I introduce prepositions using Flocabulary and their preposition video is particularly catchy - Prep, prep, prep, preposition - tells about a thing and its position. My kids could still quote it for you. I also gave them a small copy of common prepositions to refer to when we first started working with them because there are so many!
All you need are notecards or you could just do it on paper. I have the students write a subject and a verb (animals work best) on one notecard and then turn in to me and then they write a prepositional phrase on another notecard. I let them use the reference sheet if they need to. After I have both sets I mix them up and flip over one sentence card and one prepositional phrase card at a time.